ANTIVIRAL NUCLEOSIDE ANALOGUES CONTAINING A SUBSTITUTED BENZIMIDAZOLE BASE ATTACHED TO A CARBOCYCLIC RING

The present invention relates to certain purine nucleoside analogues containing a

carbocyclic ring in place of the sugar residue, pharmaceutically acceptable

derivatives thereof, and their use in medical therapy, particularly for the

treatment of certain viral infections.

Hepatitis B virus (HBV) is a small DNA containing virus which infects humans.

It is a member of the class of closely related viruses known as the

hepadnaviruses, each member of which selectively infects either mammalian or

avian hosts, such as the woodchuck and the duck.

Worldwide, HBV is a viral pathogen of major consequence. It is most common

in Asian countries, and prevalent in sub-Saharan Africa. The virus is

etiologically associated with primary hepatocellular carcinoma and is thought to

cause 80% of the world's liver cancer. In the United States more than ten

thousand people are hospitalized for HBV illness each year, an average of 250

die with fulminant disease.

The United States currently contains an estimated pool of 500,000-1 million

infectious carriers. Chronic active hepatitis will develop in over 25% of carriers,

and often progresses to cirrhosis. It is estimated that 5000 people die from

HBV-related cirrhosis each year in the USA, and that perhaps 1000 die from

HBV-related liver cancer. Even when a universal HBV vaccine is in place, the

need for effective anti-HBV compounds will continue. The large reservoir of

persistently infected carriers, estimated at 220 million worldwide, will receive

no benefit from vaccination and will continue at high risk for HBV-induced liver

disease. This carrier population serves as the source of infection of susceptible

individuals perpetuating the instance of disease particularly in endemic areas or

high risk groups such as IV drug abusers and homosexuals. Thus, there is a

great need for effective antiviral agents, both to control the chronic infection and

reduce progression to hepatocellular carcinoma.

Clinical effects of infection with HBV range from headache, fever, malaise,

nausea, vomiting, anorexia and abdominal pains. Replication of the virus is

usually controlled by the immune response, with a course of recovery lasting

weeks or months in humans, but infection may be more severe leading to

persistent chronic liver disease as outlined above.

In "Viral Infections of Humans" (second edition, Ed., Evans, A.S. (1982)

Plenum Publishing Corporation, New York), Chapter 12 describes in detail the

etiology of viral hepatitis infections.

Of the DNA viruses, the herpes group is the source of many common viral

illnesses in man. The group includes cytomegalovirus (CMV), Epstein-Barr

virus (EBV), varicella zoster virus (VZV), herpes simplex virus (HSV) and

human herpes virus 6 (HHV6).

In common with other herpes viruses, infection with CMV leads to a life-long

association of virus and host and, following a primary infection, virus may be

shed for a number of years. Clinical effects range from death and gross disease

(microcephaly, hepatosplenemegaly, jaundice, mental retardation) through

failure to thrive, susceptibility to chest and ear infections to a lack of any

obvious ill effect. CMV infection in AIDS patients is a predominant cause of

morbidity as, in 40 to 80% of the adult population, it is present in a latent form

and can be reactivated in immunocompromised patients.

EBV causes infectious mononucleosis and is also suggested as the causative

agent of nasopharyngeal cancer, immunoblastic lymphoma, Burkitt's lymphoma

and hairy leukoplakia.

VZV causes chicken pox and shingles. Chicken pox is the primary disease

produced in a host without immunity. In young children, it is usually a mild

illness characterized by a vesicular rash and fever. Shingles is the recurrent

form of the disease which occurs in adults who were previously infected with

varicella. The clinical manifestations of shingles include neuralgia and a

vesicular skin rash that is unilateral and dermatomal in distribution. Spread of

inflammation may lead to paralysis or convulsions and coma can occur if the

meninges becomes affected. In immunodefϊcient patients, VZV may

disseminate causing serious or even fatal illness.

HSV 1 and HSV 2 are some of the most common infectious agents of man.

Most of these viruses are able to persist in the host's neural cells. Once infected,

individuals are at risk of recurrent clinical manifestation of infection which can

be both physically and psychologically distressing. HSV infection is often

characterized by extensive lesions of the skin, mouth and/or genitals. Primary

infections may be subclinical although they tend to be more severe than

infections in individuals previously exposed to the virus. Ocular infections by

HSV can lead to keratitis or cataracts. Infection in the newborn, in

immunocompromised patients or penetration of infection into the central

nervous system can prove fatal. HHV6 is the causative agent of roseola

mfantum (exanthum subitum) in children which is characterized by fever and the

appearance of a rash after the fever has declined. HHV6 has also been

implicated in syndromes of fever and or rash and pneumonia or hapatitis in

immunocompromised patients.

It has now been discovered that certain substituted benzimidazole compounds as

referred to below, are useful for the treatment or prophylaxis of certain viral

infections. According to a first aspect of the present invention, novel compounds

of the formulas (I) and (1-1) are provided

wherein R ¹ is H, CH ₃ or CH ₂ OH; R ² is H or OH; R ³ is H or OH; or R ² and

R ³ together form a bond;

R ⁴ is amino, cyclopropylamino, cyclobutylamino, isopropylamino, r/-butylamino or -NR ⁸ R ⁹ where R ⁸ and R ⁹

together with the nitrogen atom to which they are attached form a 4, 5 or 6-membered heterocyclic ring; R ⁵ is H and R ⁶ and R ⁷ are

Cl, excluding the compound (±)-(lR*, 2S*, 3S*, 5S*)-5-[5,6-

Dichloro-2-(cyclopropylamino)-lH-benzimidazol-l-yl]-3-

(hyroxyomethyl)-l,2-cyclopentanediol and provided that at least one of R', R ² and R ³ is or contains OH;

Preferred compounds of formula (I) and (1-1) are those wherein R ⁴ is

cyclopropylamino, isopropylamino or tør/-butylamino and especially

isopropylamino or tert-butylamino.

Preferred compounds of Formula (I) and (1-1) are those of Formula (I A) or (IA-

1)

wherein R ² is H or OH; R ⁴ is amino, cyclopropylamino, isopropylamino, tert-

butylamino, especially isopropyl or ten -butylamino, or

-NR ⁸ R ⁹ where R ⁸ and R ⁹ together with the nitrogen atom to which they are

attached form a 4, 5 or 6 membered heterocyclic ring; R ⁵ is H; and R ⁶ and R ⁷ are

Cl, and excluding the compound (±)-(lR*, 2S*, 3S*, 5S*)-5-[5,6-Dichloro-2-

(cyclopropylamino)- 1 H-benzimidazol- 1 -y l]-3-(hyroxyomethyl)- 1 ,2-

cyclopentanediol and pharmaceutically acceptable derivatives thereof.

Particularly preferred compounds of formula (I A) and (IA-1) are those wherein

R ⁴ is cyclopropylamino, isopropylamino or tert-butylamino; R ⁵ is H; and R ⁶ and

R ⁷ are both Cl; and the pharmaceutically acceptable derivatives thereof.

It is to be understood that the present invention encompasses the particular

enantiomers depicted in formula (I) and (I-l), including tautomers of the purine,

alone and in combination with their mirror-image enantiomers. Enantiomers

depicted by formula (I) are preferred and preferably are provided substantially

free of the corresponding enantiomer to the extent that it is generally in

admixture with less than 10% w/w, preferably less than 5% w/w, more

preferably less than 2% w/w and most preferably less than 1% w/w of the

corresponding enantiomer based on the total weight of the mixture.

Enantiomers depicted by formula (I-l) are most preferred and preferably are

provided substantially free of the corresponding enantiomer to the extent

that it is generally in admixture with less than 10% w/w, preferably less than

5% w/w, more preferably less than 2% w/w and most preferably less than 1%

w/w of the corresponding enantiomer based on the total weight of the mixture.

Particularly preferred examples are:

(IR, 2S, 3S, 5S)-5-[5,6-Dichloro-2-(cyclopropylamino)-lH.-benzimidazol-l- yl]-

3-(hydroxymethyl)-l,2-cyclopentanediol;

(±)-(lR*, 2S*, 3S*, 5S*)-5-[5,6-Dichloro-2-(isopropylamino)-lH-benzimidazol-

1 -yl]-3-(hydroxymethyl)- 1 ,2-cyclopentanediol

(IR, 2S, 3S, 5S)-5-[5,6-Dichloro-2-(isopropylamino)-lH-benzimidazol-l-yl] -3-

(hydroxymethyl)- 1 ,2-cyclopentanediol;

(IR, 2S, 3S, 5S)-5-[2-(/er/-Butylamino)-5,6-dichloro-lH-benzimidazol-l-yl ]-3-

(hydroxymethyl)- 1 ,2-cyclopentanediol; and

(±)-(lR*, 2S*, 3S*, 5S*)-5-[2-(/ert-Butylamino)-5,6-dichloro-lH-benzimidazol-

1 -yl]-3-(hydroxymethyl)-l ,2-cyclopentanediol;

(lS,2R,3R,5R)-5-[5,6-Dichloro-2-(isoρropylamino)-lH-benz imidazol-l-yl]-3-

(hydroxymethy 1)- 1 ,2-cyclopentanediol;

(lS,2R,3R,5R)-5-[2-/er/-butylamino)-5,6-dichloro-lH-benzi midazol-l-yl]-3-

(hydroxymethyl)- 1 ,2-cyclopentanediol;

(±HIR*, 2S*, 3S*, 5S*)-5-[5,6-Dichloro-2-(l-azetidinyl)-lH-benzimidazol-l-

yl]-3-(hydroxymethyl)- 1 ,2-cyclopentanediol;

(IR, 2S, 3S, 5S)-5-[5,6-Dichloro-2-(l-azetidinyl)-lH-benzimidazol-l-yl]-3 -

(hydroxymethyl)-l ,2-cyclopentanediol; and

(IS, 2R, 3R, 5R)-5-[5,6-Dichloro-2-(l-azetidinyl-lH-benzimidazol-l-yl]]-3 -

(hydroxymethyl)- 1 ,2-cyclopentanediol,

and pharmaceutically acceptable salts thereof.

The compounds of formulas (I) and (I-l) above and their pharmaceutically acceptable derivatives are herein referred to as the compounds according to the invention.

In a further aspect of the invention there are provided the compounds according

to the invention for use in medical therapy particularly for the treatment or

prophylaxis of viral infections such as herpes viral infections. To date

compounds of the invention have been shown to be active against hepatitis B

virus (HBV) and cytomegalovirus (CMV) infections, although early results

suggest that the invention could also be active against other herpes virus

infections such as EBV, VZV, HSVI and II and HHV6. The compunds of the

present invention are particularly useful for the treatment or prophylaxis of

CMV infections. Also disclosed is the use of the compounds of the invention in

the preparation of a medicament for the treatment of viral infections.

Other viral conditions which may be treated in accordance with the invention

have been discussed in the introduction hereinbefore.

In yet a further aspect of the present invention there is provided:

a) A method for the treatment or prophylaxis of a hepadnaviral infection

such as hepatitis B or a herpes viral infection such as CMV which

comprises treating the subject with a therapeutically effective amount of

a compound according to the invention.

b) Use of a compound according to the invention in the manufacture of a

medicament for the treatment or prophylaxis of any of the above-

mentioned infections or conditions.

By "a pharmaceutically acceptable derivative" is meant any pharmaceutically or

pharmacologically acceptable salt, ester or salt of such ester of a compound

according to the invention, or any compound which, upon administration to the

recipient, is capable of providing (directly or indirectly) a compound according

to the invention, or an antivirally active metabolite or residue thereof.

The term heterocyclic ring means a saturated, unsaturated or partially saturated

ring containing one or more heteroatoms independently selected from nitrogen

oxygen and sulfur. Examples of such groups include azetidinyl, pyrrolidinyl and

piperidinyl.

Preferred esters of the compounds of the invention include carboxylic acid esters

in which the non-carbonyl moiety of the ester grouping is selected from straight

or branched chain alkyl, e.g. n-propyl, t-butyl, n-butyl, alkoxyalkyl (e.g.

methoxymethyl), aralkyl (e.g. benzyl), aryloxyalkyl (e.g. phenoxymethyl), aryl

(e.g. phenyl optionally substituted by halogen, Cj_4 alkyl or C\Λ alkoxy or

amino); sulfonate esters such as alkyl- or aralkylsulfonyl (e.g. methanesulfonyl);

amino acid esters (e.g. L-valyl or L-isoleucyl); and mono-, di- or triphosphate

esters. The phosphate esters may be further esterified by, for example, a Cι_20

alcohol or reactive derivative thereof, or by a 2,3-di(C6_24)acyl glycerol.

With regard to the above-described esters, unless otherwise specified, any alkyl

moiety present advantageously contains 1 to 18 carbon atoms, particularly 3 to 6

carbon atoms such as the pentanoate. Any aryl moiety present in such esters

advantageously comprises a phenyl group.

Any reference to any of the above compounds also includes a reference to a

pharmaceutically acceptable salt thereof.

Physiologically acceptable salts include salts of organic carboxylic acids such as

acetic, lactic, tartaric, malic, isethionic, lactobionic, p-aminobenzoic and

succinic acids; organic sulfonic acids such as methanesulfonic, ethanesulfonic,

benzenesulfonic and p-toluenesulfonic acids and inorganic acids such as

hydrochloric, sulfuric, phosphoric and sulfamic acids.

The above compounds according to the invention and their pharmaceutically

acceptable derivatives may be employed in combination with other therapeutic

agents for the treatment of the above infections or conditions. Examples of such

further therapeutic agents include agents that are effective for the treatment of

viral infections or associated conditions such as acyclic nucleosides (e.g.

acyclovir), immunomodulatory agents such as thymosin, ribonucleotide

reductase inhibitors such as 2-acetylpyridine 5-[(2-

chloroanilino)thiocarbonyl)thiocarbonohydrazone, interferons such as α-

interferon, l-β-D-arabinofuranosyl-5-(l-propynyl)uracil, 3'-azido-3'-

deoxythymidine, ribavirin and phosphonoformic acid. The component

compounds of such combination therapy may be administered simultaneously,

in either separate or combined formulations, or at different times, e.g.

sequentially such that a combined effect is achieved.

The compounds according to the invention, also referred to herein as the active

ingredient, may be administered for therapy by any suitable route including oral,

rectal, nasal, topical (including transdermal, buccal and sublingual), vaginal and

parenteral (including subcutaneous, intramuscular, intravenous and intradermal).

It will be appreciated that the preferred route will vary with the condition and

age of the recipient, the nature of the infection and the chosen active ingredient.

In general a suitable dose for each of the above-mentioned conditions will be in

the range of 0.01 to 250 mg per kilogram body weight of the recipient (e.g. a

human) per day, preferably in the range of 0.1 to 100 mg per kilogram body

weight per day and most preferably in the range 1.0 to 20 mg per kilogram body

weight per day. (Unless otherwise indicated, all weights of active ingredient are

calculated as the parent compound of formula (I); for salts or esters thereof, the

weights would be increased proportionally.) The desired dose is preferably

presented as two, three, four, five, six or more sub-doses administered at

appropriate intervals throughout the day. These sub-doses may be administered

in unit dosage forms, for example, containing 10 to 1000 mg, preferably 20 to

500 mg, and most preferably 100 to 400 mg of active ingredient per unit dosage

form.

Ideally, the active ingredient should be administered to achieve peak plasma

concentrations of the active compound of from about 0.025 to about 100 μM,

preferably about 0.1 to 70 μM, most preferably about 0.25 to 50 μM. This may

be achieved, for example, by the intravenous injection of a 0.1 to 5% solution of

the active ingredient, optionally in saline, or orally administered as a bolus

containing about 0.1 to about 250 mg/kg of the active ingredient. Desirable

blood levels may be maintained by a continuous infusion to provide about 0.01

to about 5.0 mg/kg/hour or by intermittent infusions containing about 0.4 to

about 15 mg/kg of the active ingredient.

While it is possible for the active ingredient to be administered alone it is

preferable to present it as a pharmaceutical formulation. The formulations of the

present invention comprise at least one active ingredient, as defined above,

together with one or more acceptable carriers thereof and optionally other

therapeutic agents. Each carrier must be "acceptable" in the sense of being

compatible with the other ingredients of the formulation and not injurious to the

patient. Formulations include those suitable for oral, rectal, nasal, topical

(including transdermal buccal and sublingual), vaginal or parenteral (including

subcutaneous, intramuscular, intravenous and intradermal) administration. The

formulations may conveniently be presented in unit dosage form and may be

prepared by any methods well known in the art of pharmacy. Such methods

include the step of bringing into association the active ingredient with the carrier

which constitutes one or more accessory ingredients. In general, the

formulations are prepared by uniformly and intimately bringing into association

the active ingredient with liquid carriers or finely divided solid carriers or both,

and then if necessary shaping the product.

Compositions suitable for transdermal administration may be presented as

discrete patches adapted to remain in intimate contact with the epidermis of the

recipient for a prolonged period of time. Such patches suitably contain the

active compound 1) in an optionally buffered, aqueous solution or 2) dissolved

and/or dispersed in an adhesive or 3) dispersed in a polymer. A suitable

concentration of the active compound is about 1% to 25%, preferably about 3%

to 15%. As one particular possibility, the active compound may be delivered

from the patch by electrotransport or iontophoresis as generally described in

Pharmaceutical Research. 3 (6), 318 (1986).

Formulations of the present invention suitable for oral administration may be

presented as discrete units such as capsules, cachets or tablets each containing a

predetermined amount of the active ingredient; as a powder or granules; as a

solution or a suspension in an aqueous or non-aqueous liquid; or as an oil-in-

water liquid emulsion or a water-in-oil liquid emulsion. The active ingredient

may also be presented as a bolus, electuary or paste.

A tablet may be made by compression or molding, optionally with one or more

accessory ingredients. Compressed tablets may be prepared by compressing in a

suitable machine the active ingredient in a free-flowing form such as a powder

or granules, optionally mixed with a binder (e.g. povidone, gelatin,

hydroxypropylmethyl cellulose), lubricant, inert diluent, preservative,

disintegrant (e.g. sodium starch glycollate, cross-linked povidone, cross-linked

sodium carboxymethyl cellulose) surface-active or dispersing agent. Molded

tablets may be made by molding in a suitable machine a mixture of the

powdered compound moistened with an inert liquid diluent. The tablets may

optionally be coated or scored and may be formulated so as to provide slow or

controlled release of the active ingredient therein using, for example,

hydroxypropylmethyl cellulose in varying proportions to provide the desired

release profile. Tablets may optionally be provided with an enteric coating, to

provide release in parts of the gut other than the stomach.

Formulations suitable for topical administration in the mouth include lozenges

comprising the active ingredient in a flavored basis, usually sucrose and acacia

or tragacanth; pastilles comprising the active ingredient in an inert basis such as

gelatin and glycerin, or sucrose and acacia; and mouthwashes comprising the

active ingredient in a suitable liquid carrier.

Formulations for rectal administration may be presented as a suppository with a

suitable base comprising for example cocoa butter or a salicylate.

Formulations suitable for vaginal administration may be presented as pessaries,

tampons, creams, gels, pastes, foams or spray formulations containing in

addition to the active ingredient such carriers as are known in the art to be

appropriate.

Formulations suitable for parenteral administration include aqueous and non-

aqueous isotonic sterile injection solutions which may contain anti-oxidants,

buffers, bacteriostats and solutes which render the formulation isotonic with the

blood of the intended recipient; and aqueous and non-aqueous sterile

suspensions which may include suspending agents and thickening agents. The

formulations may be presented in unit-dose or multidose sealed containers, for

example, ampules and vials, and may be stored in a freeze-dried (lyophilized)

condition requiring only the addition of the sterile liquid carrier, for example

water for injections, immediately prior to use. Extemporaneous injection

solutions and suspensions may be prepared from sterile powders, granules and

tablets of the kind previously described.

Preferred unit dosage formulations are those containing a daily dose or unit,

daily sub-dose, as herein above recited, or an appropriate fraction thereof, of an

active ingredient.

It should be understood that in addition to the ingredients particularly mentioned

above the formulations of this invention may include other agents conventional

in the art having regard to the type of formulation in question, for example,

those suitable for oral administration may include such further agents as

sweeteners, thickeners and flavoring agents.

The present invention further includes the following process, depicted

schematically, for the preparation of compounds of this invention

Base, e.g., ₂ CC >3 or tπethylammo Solvent such as t-butanol. dioxane. dimethytforrnarnide

(Wherein L is a leaving group, e.g., halogen, in particular Chloro)

1) R ⁴ Cθ ₂ H, heat (for R*=H. alkyl pemuoroalkyl)

(I)

2) N-hak.succinirn.de (for R shalogen)

3) cyanogen bromide (for R =MH2)

Thus, according to a further feature of the present invention we provide a

process for the preparation of compounds of formulae (I) and (I-l) alone or in combination with their mirror image enantiomers, and their pharmaceutically

acceptable derivatives which comprises (A) reacting

or the mirror image enantiomer thereυi, wm.

a) either a compound of formula R CO ₂ H where R ⁴ is H, C i -4 alkyl or C i -

4 perfluoroalkyl preferably at an elevated temperature or a compound of

formula R ⁴ C(OR) ₃ wherein R ⁴ is H, Ci-4 alkyl or C 1-4 perfluoroalkyl

and R is Ci-4 alkyl, preferably at ambient temperature and in an acidic

medium, to form a compound of formula (I) or (I-l) in which R ⁴ is H, or

b) cyanogen bromide to form a compound of formula (I) or (I- 1 ) in which R ⁴ is NH2; or

(B) a) converting a compound of formula (I) or (I-l) in which R ⁴ is hydrogen

into a further compound of formula (I) or (I-l) in which R ⁴ is a leaving group

for example by treatment with an N-(C1, Br or I) succinimide to form a

compound in which R ⁴ is Cl, or Br and

b) converting a compound of formula (I) or (I-l ) in which R ⁴ is Cl, or Br

into a further compound of formula (I) or (I-l) in which R ⁴ is an amino or

substituted amino group -NR ⁸ R ⁹ as defined above, by treatment with a Ci-4

alkylamine or di-C alkylamine or R ⁸ R ⁹ NH where R ⁸ and R ⁹ are defined as

above or

(C) reacting a compound of formula

(wherein R ⁴ , R$, R6 and R? are as herebefore defined) or a functional

equivalent thereof with a compound of formula

wherein Rl, R^ and R^ are as defined above and L is a leaving group,

for example an organosulphonyloxy (e.g. p-toluenesulphonyloxy or

methanesulphonyloxy), halogen or triflate (OSO2CF3) group), for example in

the presence of a base such as sodium carbonate or sodium hydride in a solvent

such as dimethylformamide, advantageously at an elevated temperature e.g. 80-

100°C, to form a compound of formula (I) or (I-l) in which R ⁴ is hydrogen,

halogen or NR ⁸ R ⁹ ; and optionally converting a compound of formula (I) or (I-l)

into a pharmaceutically acceptable derivative thereof.

Alternatively in process (C) above the compound of formula (IV) may be

replaced with a compound in which the L and R^ groups are replaced with a

cyclic sulphate group.

All of the structures shown above are intended to represent the enantiomers

depicted as well as their mirror image isomers, as well as mixtures thereof.

Thus, the present invention is intended to encompass both the racemates and the

pure enantiomers, substantially free of their mirror-image isomers.

A compound of formula (I) or (I-l) may be converted into a pharmaceutically

acceptable ester by reaction with an appropriate esterifying agent, e.g. an acid

halide or anhydride. The compound of formula (I) or (I-l) including esters

thereof, may be converted into pharmaceutically acceptable salts thereof in

conventional manner, e.g. by treatment with an appropriate acid. An ester or salt

of an ester of formula (I) or (I-l) may be converted into the parent compound,

e.g. by hydrolysis.

The following Examples are intended for illustration only and are not intended

to limit the scope of the invention in any way. The term 'active ingredient' as

used in the examples means a compound of formula (I) or (I-l) or a

pharmaceutically acceptable derivative thereof.

Example A:

Table ForroμlatiQng

The following formulations A and B were prepared by wet granulation of the

ingredients with a solution of povidone, followed by addition of magnesium

stearate and compression.

Formulation A mg/tablet mg/tablet

00 Active ingredient 250 250

( ) Lactose B.P. 210 26

(c) Povidone B.P. 15 9

(d) Sodium Starch GlycoUate 20 12

(e) Magnesium Stearate

500 300

For v lation B mg/tablet mg/tablet

(a) Active ingredient 250 250

(b) Lactose 150 -

(c) Avicel PH 101 60 26

(d) Povidone B.P. 15 9

(e) Sodium Starch GlycoUate 20 12

(0 Magnesium Stearate

500 300

Formulation C, mg/tablet

Active ingredient 100 Lactose 200 Starch 50

Povidone 5 Magnesium stearate 4

359

The following formulations, D and E, were prepared by direct compression of

the admixed ingredients. The lactose used in formulation E was of the direct

compression type (Dairy Crest - "Zeparox").

Formulation D mg/tablet

Active Ingredient 250 Pregelatinised Starch NF15

400

Formulation E mg/tablet

Active Ingredient 250 Lactose 150 Avicel 100 500

Formulation F (Controlled Release Formulation)

The formulation was prepared by wet granulation of the ingredients (below)

with a solution of povidone followed by the addition of magnesium stearate and

compression.

mg/tablet

(a) Active Ingredient 500

(b) Hydroxypropylmethylcellulose 112 (Methocel K4M Premium)

(c) Lactose B.P. 53

(d) Povidone B.P.C. 28

(e) Magnesium Stearate _Z 700

Example B:

Capsule Formulations

Formulation A

A capsule formulation was prepared by admixing the ingredients of Formulation D in Example 1 above and filling into a two-part hard gelatin capsule.

Formulation B (infra) was prepared in a similar manner.

Formulation B

mg/capsuie

(a) Active ingredient 250

( ) Lactose B.P. 143

(c) Sodium Starch GlycoUate 25

(d) Magnesium Stearate I

420

Formulation C mg/capsule

(a) Active ingredient 250

(b) Macrogol 4000 BP 2---.

600

Capsules were prepared by melting the macrogol 4000 BP, dispersing the active

ingredient in the melt and filling the melt into a two-part hard gelatin capsule.

Formulation D mg/capsule Active ingredient 250

Lecithin 100

Arachis Oil 122

450

Capsules were prepared by dispersing the active ingredient in the lecithin and

arachis oil and filling the dispersion into soft, elastic gelatin capsules.

Formulation E (Controlled Release Capsule)

The following controlled release capsule formulation was prepared by extruding

ingredients a, b and c using an extruder, followed by spheronisation of the

extrudate and drying. The dried pellets were then coated with release-

controlling membrane (d) and filled into a two-piece, hard gelatin capsule.

mg/capsule

(a) Active Ingredient 250

(b) Microcrystalline Cellulose 125

(c) Lactose BP 125

(d) Ethyl Cellulose .11 513

Example C:

Iniectahle Formulation

Formulation A.

Active ingredient 0.200 g

Hydrochloric acid solution, 0. IM -q.s. to pH 4.0 to 7.0

Sodium hydroxide solution, 0.1 M q.s. to pH 4.0 to 7.0

Sterile water q.s. to 10ml

The active ingredient was dissolved in most of the water (35°-40°C) and the pH

adjusted to between 4.0 and 7.0 with the hydrochloric acid or the sodium

hydroxide as appropriate. The batch was then made up to volume with the water

and filtered through a sterile micropore filter into a sterile 10ml amber glass vial

(type 1) and sealed with sterile closures and overseals.

Formulation B.

Active ingredient 0.125 g

Sterile, pyrogen-free, pH 7 phosphate buffer, q.s. to 25 ml

Example D:

Intramuscular injection

Active Ingredient 0.20 g

Benzyl Alcohol 0.10 g

Glycofurol 1.45 g

Water for Injection q.s. to 3.00 ml

The active ingredient was dissolved in the glycofurol. The benzyl alcohol was

then added and dissolved, and water added to 3 ml. The mixture was then

filtered through a sterile micropore filter and sealed in sterile 3 ml amber glass

vials (type 1).

Example E:

Syrup

Active ingredient 0.2500 g

Sorbitol Solution 1.5000 g

Glycerol 2.0000 g

Sodium Benzoate 0.0050 g

Flavour, Peach 17.42.3169 0.0125 ml

Purified Water q.s. to 5.0000 ml

The active ingredient was dissolved in a mixture of the glycerol and most of the

purified water. An aqueous solution of the sodium benzoate was then added to

the solution, followed by addition of the sorbitol solution and finally the flavour.

The volume was made up with purified water and mixed well.

Example F:

Suppository

mg/suppository A ive Ingredient (63lm)* 250

Hard Fat, BP (Witepsol H15 - Dynamit Nobel) 1ZZ2

2020

*The active ingredient was used as a powder wherein at least 90% of the

particles were of 631 m diameter or less.

One-fifth of the Witepsol HI 5 was melted in a steam-jacketed pan at 45 °C

maximum. The active ingredient was sifted through a 2001 m sieve and added to

the molten base with mixing, using a silverson fitted with a cutting head, until a

smooth dispersion was achieved. Maintaining the mixture at 45 °C, the

remaining Witepsol HI 5 was added to the suspension and stirred to ensure a

homogeneous mix. The entire suspension was passed through a 2501 m stainless

steel screen and, with continuous stirring, was allowed to cool to 40 °C. At a

temperature of 38°C to 40 °C, 2.02 g of the mixture was filled into suitable, 2 ml

plastic moulds. The suppositories were allowed to cool to room temperature.

Example G:

E≤ssaris≤

mg/pcssary

Active ingredient (63lm) 250

Anhydrate Dextrose 380

Potato Starch 363

Magnesium Stearate Z

1000

The above ingredients were mixed directly and pessaries prepared by direct

compression of the resulting mixture.

Antiviral Testing

1. Anti-HCMV

Human cytomegalovirus (HCMV) is assayed in monolayers of MRC5

cells (human embryonic lung) in multiwell trays. Activity of compounds

is determined in the plaque reduction assay, in which a cell monolayer is

infected with a suspension of HCMV. A range of concentrations of the

compound to be tested (of known molarity) is then incorporated into the

carboxymethyl cellulose overlay. Plaque numbers of each concentration

are expressed as percentage of the control and a dose-response curve is

drawn. From this curve the 50% inhibitory concentration (IC50) is

estimated.

Anti-HCMV Activitv

Compound I£5 Iϋ }

Ex. 4 1.9

2. Anti-HBV

a. Overview:

Anti-HBV activity of compounds of formula (I) and (I-l)

was determined with a high-capacity assay for assessing efficacy.

Supematants from growing HBV-producing cells (HepG2 2.2.15,

P5A cell line) in 96-well plates are applied to microtiter plate

wells which have been coated with a specific monoclonal

antibody to HBV surface antigen (HBsAg). Virus particles

present in the supematants bind to the antibody and remain

immobilized while other debris is removed by washing. These

virus particles are then denatured to release HBV DNA strands

which are subsequently amplified by the polymerase chain

reaction and detected with a colorimetric hybrid-capture assay.

Quantitation is achieved through fitting of a standard curve to

dilutions of a cell supernatant with known HBV DNA content.

By comparing HBV DNA levels of untreated control cell

supematants with supematants containing a compound of formula

(I) or (I-l), a measure of anti-HBV effectiveness is obtained.

b. Immunoaffinitv Capture of HBV:

HBV producer cells, 2500 cells/well, were seeded in 96-

well culture dishes in RPMI/10% fetal bovine serum/2mM

glutamine (RPMI/10/2:). Media were replenished on days 1, 3, 5,

and 7 with dilutions of a compound of formula (I) or (I-l) in

RPMI/10/2 to a final volume of 150 uL. Fifty uL of mouse

monoclonal anti-HBsAG antibody (lOug/mL in PBS) were added

to each well of a round-bottom microtiter plate. After incubation

overnight at 4°C, the solutions were aspirated and replaced with

100 uL of 0.1% BSA in PBS. Samples were incubated for

2 hours at 37°C and washed three times with PBS/0/01% Tween-

20 (PBS/T) using a Nunc Washer. Ten uL of 0.035% Tween 20

in PBS were then added to all wells by Pro/Pette. Cell

supematants (25 uL) containing extracellular virion DNA were

transferred into wells by Pro/Pette; the final Tween concentration

is 0.01%. Twenty-five uL HBV standard media dilutions in

RPMI/10/2 were added to 2 rows of wells to serve as an internal

standard curve for quantitation, and the plates were sealed and

incubated at 4°C overnight. Samples were washed 5 times with

PBS/T and 2 times with PBS, aspirating the last wash. Next,

25 uL of 0.09N NaOH 0.01% NP40 were added to each well by

Pro/Pette, and the sample wells were sealed and incubated at

37 °C for 60 minutes. Samples were then neutralized with 25 uL

of 0.09N HCl/100 mM tris (pH 8.3).

c. Polymerase Chain Reaction (PCR):

Polymerase chain reaction (Saiki, R.K. sl al-, Science, 239

(4839) 487-91 (1988)) was carried out on 5uL samples, using a

Perkin Elmer PCR kit. PCR is performed in "MicroAmp tubes"

in a final volume of 25 uL. Primers were chosen from conserved

regions in the HBV genome, as determined by alignment of

several sequences. One primer is biotinylated at the 5-prime end

to facilitate hybrid-capture detection of the PCR products. All

primers were purchased from Synthecell Corp., Rockville, MD

20850.

d. Hvbrid-Capture Detection of PCR Products:

PCR products were detected with horse radish peroxidase-

labeled oligonucleotide probes (Synthecell Corp., Rockville, MD

20850), which hybridize to biotinylated strands of denatured PCR

products directly in streptavidin-coated microtiter plate wells,

using essentially the method of Holodiniy, M. slal.,

BioTechniques. 12 (1) 37-39 (1992). Modifications included the

use of 251 PCR reaction volumes and sodium hydroxide

denaturation instead of heat. Simultaneous binding of the biotin

moiety to the plate-bound streptavidin during the hybridization

serves to "capture" the hybrids. Unbound labeled probes were

washed away before colorimetric determination of the bound

(hybridized) horse radish peroxidase. Quantities of HBV DNA

present in the original samples were calculated by comparison

with standards. These values were then compared to those from

untreated cell cultures to determine the extent of anti-HBV

activity.

IC50 (the median inhibitory concentration) is the amount of compound which produces a 50 percent decrease in HBV

DNA. The approximate IC50 of the compounds of Examples 4,

13 and 69 are tabulated.

Anti-HCMV Activity

Compound IC5 ₎ (μM)

Ex. 4 0.74, 2.5

Ex. 32 1.3, 0.79

Ex. 33 0.44, 0.50

Ex. 40 2.0, 1.4

Ex. 41 0.4, 0.40 ganciclovir (control) 1.1 (averag

Example 1

r± lR*. 2S*. 3S». 5S*)-3-(Acetoxymethyl)-5-(4.5-dichloro-2-nitroanilino)-

1.2-cvclopentanediyl diacetate

(±)-(lR*, 2S*, 3R*, 4R*)-tert-Butyl N-[2,3-dihydroxy-4-(hydroxymethyl)

-1-cyclopentyl] carbamate (6.27 g, 25.1 mmol) and IN hydrochloric acid

(50 mL) were stirred overnight. The resulting clear solution was concentrated in

vacuo and dried by evaporation of methanol and ethanol to give the

hydrochloride of (±)-(lS*, 2R*, 3S*, 5R*)-3-amino-5-(hydroxy-

methyl)-l,2-cyclopentanediol as a solid foam (4.73 g). This solid foam was

refluxed vigorously with triethylamine (7.5 g, 75 mmol), l,2,4-trichloro-5-nitro-

benzene (5.84 g, 25.0 mmol as 97%, Aldrich), and 2-methoxyethanol (75 mL)

for 24 hours. The resulting black mixture was evaporated to dryness and the

residue chromatographed on silica gel and product eluted with

methanol :chloroform / 1 :10 as a dark orange glass (6.9 g). Crystallization from

ethanol- water gave orange powder (3.00 g) which was stirred in acetic anhydride

(3.0 mL) - pyridine (20 mL) at ambient temperature overnight. Evaporation of

volatiles, followed by crystallization from ethyl acetate-hexanes gave title

compound as orange needles (2.82 g, 24%), m.p. 153-156°C; ΪH-NMR

(DMSO-α_6)δ: 8.25 and 7.51 (both s, 1 each, C6H2), 8.07 (d, J=7.8 Hz, 1, NH),

5.23 and 5.09 (both m, 2, 2 CHO), 4.3 (m, 1, CHN), 4.2-4.0 (m, 2, CH2O),

2.5-2.35 (m, 2, 2CH), 2.04, 2.03, 2.02 (all s, 9, 3CH3CO), 1.5-1.4 (m, 1, CH).

Anal- Calcd. for Ci5H20N2O5Cl2: C, 46.67; H, 4.35; N, 6.05; Cl, 15.31.

Found: C, 46.66; H, 4.37; N, 6.02; Cl, 15.38.

Example 2

(±)-(lR*. 2S*. 3S*. 5S*)-3-(Acetoxymethyl)-5-(5.6-dichloro-lH-benzimidazol

-l-vl)-l .2-cvclopentanedivl diacetate

(±)-(lR*, 2S*, 3S*,

5S*)-3-(Acetoxymethyl)-5-(4,5-dichloro-2-nitroanilino)

-1,2-cyclopentanediyl diacetate (2.75 g, 5.93 mmol) and Raney nickel (aqueous

slurry, Aldrich, 300 mg wet) in isopropanol (250 mL) was shaken under

hydrogen (40 psi) in a Parr shaker for 2.25 hours. Catalyst was filtered off with

Celite and the filtrate acidified with 98% formic acid (5 mL) and concentrated to

an orange oil. The oil was diluted with additional 98% formic acid (45 mL) and

the resulting orange solution refluxed for 40 minutes. Volatiles were removed

and the remaining dark oil dissolved in chloroform (100 mL). The chloroform

solution was washed with saturated aqueous sodium bicarbonate (3 x 10 mL),

dried (sodium sulfate), and evaporated to a foam which was chromatographed on

silica gel. Title compound eluted with methanol: chloroform / 3:97 as a white

foam from ethyl acetate (2.26 g, 86%); -NMR (DMSO-_i6)δ: 8.57, 8.17, 7.97

(all s, 1 each, 3 benzimidazole CH), 5.6 (m, 1, CHO), 5.3-5.1 (m, 2, CHO and

CHN), 4.35-4.15 (m, 2, CH2O), 2.6-2.4 (m overlapping solvent, 2 CH), 2.10,

2.06, 1.92 (all s) overlapped by 2.0 (m, total 10, 3CH3CO and CH).

Anal. Calcd. for C19H2ON2O6CI2: C, 51.49; H, 4.55; N, 6.32; Cl, 16.00.

Found: C, 51.39; H, 4.58; N, 6.22; Cl, 16.07.

Example 3

(±W1R*. 2S*. 3S*.

5S*)-3-(Acetoxvmethvl)-5-(2-bromo-5.6-dichloro-lH-benzimi dazol-

1 -vl)- 1.2-cvclopentanedivl diacetate

(±)-(lR*, 2S*, 3S*,

5 S * )-3 -( Acetoxymethyl)-5 -(5 ,6-dichloro- 1 H-benzimidazol-

l-yl)-l,2-cyclopentanediyl diacetate (1.32 g, 2.98 mmol) in dry N,

N-dimethylformamide (6 mL) was heated to 60°C. Portions (c_a. 1 mmol each)

of N-bromosuccinimide (1.59 g, 8.93 mmol) were added over 5 hours. Heating

was continued for an additional 4 hours. Volatiles were removed in vacuo and

the residue chromatographed on silica gel. Title compound eluted with 1 :1

hexane-ethylacetate as a tan powder (1.1 g, 69%), ^H-NMR identical with

recrystallized sample. Such a sample was recrystallized from ethanol-water to a

white powder, m.p. 156-159°C; -NMR (DMSO-i6)δ: 8.34, 7.97 (both s,

1 each, 2 benzimidazole CH), 5.6 (m, 1, OCH), 5.3 (m, 1, OCH), 5.2-5.0 (m, 1,

NCH), 4.4-4.2 (m, 2, OCH2), 2.7-2.5 (m, 1, CH), 2.4-2.0 (m) overlapping 2.1

and 2.07 (both s, total 8, CH2 and 2CH3CO), 1.92 (s, 3, CH3CO); mass

spectrum (CI): 527 (6.6), 525 (45), 523 (100), 521 (65, M+l), 257 (48, M-B).

Anal- Calcd. for C19H19N2O6 BrCl2: C, 43.71; H, 3.67; N, 5.37; total

halogen as Br, 45.91. Found: C, 43.64; H, 3.63; N, 5.30; total halogen as Br,

45.77.

Example 4

(±WIR*. 2S*. 3S*. 5S*)-5-(2-Bromo-5.6-dichloro-lH-benzimidazol-lyl)-3-

(hvdroxymethyl)- 1.2-cyclopentanediol

(±)-(lR*, 2S*, 3S*,

5 S * )-3-(Acetoxymethyl)-5-(2-bromo-5 ,6-dichloro- 1 H-

benzimidazol-l-yl)-l,2-cyclopentanediyl diacetate (600 mg, 1.15 mmol) was

added to a stirred mixture of sodium carbonate (122 mg) in water

(2 mL)-ethanol (10 mL)-methanol (10 mL). After 2.5 hours at ambient

temperature, the pH was adjusted to 7 with glacial acetic acid. Volatiles were

removed in vacuo and the residue triturated with water (5 mL) and filtered to

give white solid. Recrystallization of the solid from 1:1 ethanol-methanol gave

title compound as a white powder (282 mg, 62%), m.p. 208-211°C; ^} H-NMR

(DMSO-d.6)δ: 8.23, (s, 1, benzimidazole H7), 7.95 (s, benzimidazole H4), 5.13

(t, J=4.1 Hz, 1, CH2OH), 5.03 (d, J=6.2 Hz, 1, OH), 5.0-4.85 (m, 1, H5), 4.71

(d, J=3.5 Hz, 1, OH), 4.55-4.45 (m, 1, HI), 3.85-3.80 (m, 1, H2), 3.7-3.6 and

3.55-3.45 (both m, 1 each, OCH2), 2.2-1.95 (m, 3, H3 and 2H4); mass spectrum

(CI): 395 (M+l).

Anal- Calcd. for Ci3Hι3N2θ3Cl2Br: C, 39.43; H, 3.31; N, 7.07; total

halogen as Br, 60.52. Found: C, 39.50; H, 3.33; N, 7.02; total halogen as Br,

60.61.

Example 5

(lα. 3β. 4β)-(3.4-Dihydroxy-l-cyclopentyl) methyl benzoate

To a stirred, cooled (0°C) solution of 4-hydroxymethylcyclopentene

(J.-P. Depres and A. E. Green, J. Org. Chem. 1984. 49, 928-931, and references

therein) (37.0 g, 276 mmol) in pyridine (450 mL) was added benzoylchloride

(32.1 mL, 276 mmol) over 30 minutes. The resulting mixture was stirred at

room temperature for 1.25 hours. Water (50 mL) was added and the volatiles

removed in vacuo. The residual oil was dissolved in chloroform and the

solution extracted with water and then dried over sodium sulfate. Evaporation

of solvent gave (3-cyclopenten-l-yl)methylbenzoate as a yellow oil (53.94 g,

91%), sufficiently pure for use; H-NMR (DMSO-d _. 6)δ: 7.98, 7.67, 7.56 (m, 5,

C6H5), 5.72 (s, 2, CH=CH), 4.19 (m, 2, OCH2), 2.71 (m, 1, CH), 2.56-2.77 (m,

overlapping solvent, 2CH), 2.21-2.14 (m, 2, 2CH).

(3-Cyclopenten-l-yl)methyl benzoate (37.6 g, 0.161 mol) in acetone

(200 mL) was added dropwise over 2 hours to a stirred solution of

N-methylmorpholine-N-oxide (33.1 g, 60% in water, 0.169 mol), osmium

tetroxide (2.5% in t-butanol, Aldrich, 3.0 mL), and acetone (200 mL) at ambient

temperature. Stirring was continued for an additional 16 hours. Chloroform

(500 mL) and water (150 mL) were added. The organic layer was separated,

washed with cold IN hydrochloric acid (2 x 150 mL) and then with saturated

aqueous sodium bicarbonate (100 mL) and dried (MgSO-|). Volatiles were

removed and the residual solid crystallized from toluene (200 mL) to give title

compound as white crystals (26.9 g, 73%), m.p. 92-94°C; ^] H-NMR

(DMSO-d6)δ: 7.96, 7.65, 7.56 (m, 5, C6H5), 4.38 (d, J=4.1 Hz, 2, 2OH), 4.14

(d, J=6.6 Hz, 2, CH2O), 3.90 (m, 2, 2 OCH), 2.58 (m overlapping solvent, CH),

1.75 (m, 2, 2CH), 1.55 (m, 2, 2CH).

Δnal. Calcd. for Ci3Hi6O4: C, 66.09; H, 6.83. Found: C, 66.19; H,

6.86.

Concentration of mother liquors yielded 10.33 g of white solid which

contained additional title compound contaminated by (±)-(l_, 3_,

4_)-(3,4-dihydroxy-l-cyclopentyl)methyl benzoate, ratio approximately 2:3 by

^-NMR.

Example 6

(3a-oc. 5tt. 6a-α)-(Tetrahvdro-4H-cvclθDenta-l ■3-2-dioxathiol-5-vl)methvl

benzoate S-oxide

Thionyl chloride (6.04 g, 50.8 mmol) was added to a solution of (IB, 3a,

4a)-(3,4-dihydroxy-l-cyclopentyl)methyl benzoate (10.0 g, 42.3 mmol) in

carbon tetrachloride (150 mL). The solution was refluxed for 1.5 hours. Solvent

was evaporated to leave title compound as a thick oil sufficiently pure for use

(see following example). Such a sample crystallized as a waxy solid from

toluene, m.p. 48-57°C; ^J H-NMR (DMSO-dό)δ: 7.96, 7.66, 7.52 (m, 5, C6H5),

5.46 and 5.32 (both m, 1, 2 OCH, due to ca 1 :1 mixture of isomeric S-oxides),

4.28 (m, 2, OCH2), 2.90 and 2.43 (both m, 1, CH of two isomeric S-oxides),

2.10 and 1.74 (both m, 4, 4CH).

ΔDaJ Calcd. for Ci3Hι4θ5S: C, 55.31 ; H, 5.00; S, 1 1.36. Found: C,

55.41; H, 5.04; S, 11.30.

Example 7

(3a-tt. 5ce. 6a-c.)-(Tetrahvdro-4H-cvclopenta-l .3-2-dioxathiol-5-vl)methvl

benzoate S. S-dioxide

(3a-α. 5α. 6a-α-(Tetrahvdro-4H-cvclopenta-l .3.2-dioxathiol-5-vl)methvl

benzoate S-oxide (previous example, 42.3 mmol) was stirred in carbon

tetrachloride (40 mL)-acetonitrile (40 mL)-water (60 mL) while sodium

metaperiodate (8.98 g, 42.3 meq) and ruthenium trichloride (44 mg, 0.21 meq)

were added. Additional sodium metaperiodate (179 mg) was added

after 30 minutes to bring the reaction to completion as judged by TLC (silica

gel, methanol: chloroform / 1 : 19, visualized in iodine). After a total of 1.0 hour,

methylene chloride (300 mL) was added. The organic layer was separated and

the aqueous layer extracted with additional methylene chloride (300 mL). The

combined organic layers were washed with saturated aqueous sodium

bicarbonate (100 mL), then saturated aqueous sodium chloride (100 mL), dried

(MgSO4) and concentrated in vacuo to give title compound as white powder

(12.37 g, 98%), m.p. 114-1 19°C; ΪH-NMR (DMSO-d.6)δ: 8.02, 7.70, 7.55 (all

m, 5, C6H5), 5.62 (m, 2, OCH), 4.34 (d, J=5.8 Hz, 2, OCH2), 2.79-2.64 (m, 1,

CH), 2.32-2.21 and 1.97-1.79 (m, 4, 2 CH2).

Anal. Calcd. for Ci3Hι4Sθ6: C, 52.35; H, 4.73; S, 10.75. Found: C, 52.32; H, 4.73; S, 10.69.

Example 8

⁽ ±WlR*. 2R*. 4S* ⁾ -2- ⁽ 5.6-Dich1oro-lH-benzimidazol-l-yl)-4-n vdroxymethyl) cvclopentanol

Sodium hydride (416 mg, 10.4 meq as 60% oil dispersion) was added to a

solution of 5,6-dichlorobenzimidazole (L. B. Townsend and G. R. Revankar,

ϊϊ. 1970. 70, 389, and references therein) (1.50 g, 8.00 mmol) in dry

N,N-dimethylformamide (35 mL). The mixture was stirred for 45 minutes at

25°C. (3a-α, 5α, 6a-α-(tetrahydro-4H-cyclopenta-l,3-2-dioxathiol-5-yl)methyl

benzoate S, S-dioxide (3.05 g, 10.2 mmol) (prepared in Examples 7, 8 and 9)

was added in portions over 5 hours. Stirring was continued overnight at ambient

temperature. Volatiles were removed in vacuo and the residual oil dissolved in

1,4-dioxane (130 mL)-water (10 mL) at reflux with 4M sulfuric acid (2.3 mL).

After 10 minutes at reflux, the solution was basified with 5N sodium hydroxide,

heated for an additional hour at 50°C, and then neutralized with additional acid.

Evaporation of volatiles in vacuo gave residual solids which were extracted with

chloroform to remove unreacted 5,6-dichlorobenzimidazole and then crystallized

from ethanol-water to give title compound as white powder (2.09 g, 87%).

Recrystallization of such a sample from ethanol-water gave title compound as

white granules, m.p. 244-245°C; ^-NMR (DMSO-dό)δ: 8.47, 8.05, 7.93 (all s,

3, aryl CH), 5.19 (d, J=5.3 Hz, 1, CHOH), 4.71 (t, J=5.3 Hz, 1, CH2OH), 4.6-4.5

(m, 1, NCH), 4.37-4.25 (m, 1, OCH), 3.41 (m, 2, OCH2), 2.4-2.2 and 1.95-1.62 (m, 5, 5CH).

Anal- Calcd. for C13H14N2O2CI2 O.O2 C2H5OH: C, 51.85; H, 4.71; N,

9.27; Cl, 23.47. Found: C, 51.87; H, 4.74; N, 9.28; Cl, 23.60.

Example 9

(±)-(lR*. 2R*. 4S*)-4-(Acetoxymethyl)-2-(5.6-dichloro-lH-benzimidazol-1 -yl)

cvclopentvl acetate

(-t)-(lR*, 2R*,4S*)-2-(5,6-Dichloro-lH-benzimidazol-l-yl)- 4-(hydroxymethyl)

cyclo-pentanol (7.80 g, 25.8 mmol) was dissolved in pyridine (50 mL)-acetic

anhydride (50 mL) and the solution stirred overnight. Volatiles were removed in

vacuo and the residual oil partitioned between methylene chloride (150 mL) and

saturated aqueous sodium bicarbonate (100 mL). The organic layer was dried

(sodium sulfate) and evaporated to a glass (9.91 g, 99%); ^J H-NMR (DMSO-d.6)

δ: 8.58, 8.08, 7.96 (s, 3, aryl CH), 5.39-5.32 (m, 1, OCH), 5.09-5.04 (m, 1,

NCH), 4.1 1 (d, J=6.6 Hz, 2, OCH2), 2.59-2.50 (m overlapping solvent, CH),

2.41-2.35 (m, 1, CH), 2.17-1.86 (m overlapping 2.06 and 1.94, both s, total 9,

3CH and 2CH3CO).

Anal. Calcd. for C17H18N2O2CI2 O.I CH2CI2: C, 52.96; H, 4.70; N,

7.26; Cl, 18.55. Found: C, 52.86; H, 4.74; N, 7.25; Cl, 18.50.

Example 10

(±HlR*, 2R*,4S*)-4-(Aget9χy _m gt yl)-2-(2-t>romo-5,6-dig loro- 1 H-benzimidazol-l -vl)-cvclopentvl acetate

N-Bromosuccinimide (4.54 g, 25.5 mmol) was added to a solution of

(±)-(lR*, 2R*,4S*)-4-(acetoxymethyl)-2-(5,6-dichloro-lH-benzimidazol-l -yl)

cyclopentyl acetate (8.95 g, 23.2 mmol) in dry N,N-dimethylformamide

(46 mL). The solution was maintained at ca. 70°C (oil bath) for 5 hours.

Volatiles were removed in vacuo and the residual orange syrup

chromatographed on silica gel. Title compound was eluted with chloroform as a

pale yellow solid (5.14 g, 48%), m.p. 122-125°C; iH-NMR (DMSO-d6)δ: 8.16

(s, 1, benzimidazole H7), 7.95 (s, 1, benzimidazole H4), 5.60-5.55 (m, 1, OCH),

5.12-5.03 (m, 1, NCH), 4.15 (d, J=6.3 Hz, 2, OCH2), 2.66-2.60 (m, 1, CHCH2),

2.29-2.14 (m, 3, CH), 2.06 (s, 3, CH3CO), 1.93 (s overlapped by m, 4, CH3CO

+ CH); mass spectrum (CI): 469 (5.8), 467 (37.5), 465 (95), 463 (54, M+l), 199

(100, M-B).

Anal. Calcd. for Ci7Hι7N2Cl2Brθ4: C, 43.99; H, 3.69; N, 6.04; total

halogen as Br, 51.65. Found: C, 44.06; H, 3.70; N, 5.97; total halogen as Br, 51.74.

Example 11

Analysis of (-)-(lS. 4R)-4-Amino-2-cvclopentene-l -methanol and its

enantiomer. (+)-(! R. 4S)-4-amino-2-cvclopentene-l -methanol

Samples of the title compounds were characterized by the method of Bruckner,

H., Wittner, R., and Godel, H., "Automated Enantioseparation of Amino Acids

by Derivatization with o-Phthaldialdehyde and N-Acylated Cysteines", J.

Chrom., 476 (1989) 73-82. Using o-phthaldialdehyde and N-acetyl-L-cysteine

as derivatizing reagents. The chromatographic separation used an Optima II

ODS 100 x 4.5 mm, 3 μm column (III Supplies Co., Meriden, CT) and gradient

elution at 0.9 mL/min using initially 100% sodium acetate buffer, 40 mM,

pH 6.5, with a linear ramp to 18% acetonitrile over 15 minutes and a subsequent

hold at 18% acetonitrile for 15 minutes. Detection was at 338 nm. Samples

were dissolved in 0.1 molar borate buffer, pH 10.4. The identity and purity of

the samples was established by comparison with authentic standards (see

EP 434450 (June 26, 1991)). The retention time of the (IS, RS) isomer was

about 21 minutes. The retention time of the (IR, 4S)- isomer was about

22 minutes.

Example 12

(±)-cis-4-Amino-2-cvclopentene- 1 -methanol

A dry, 2L, three-neck flask was equipped with a mechanical stirrer, thermometer

with gas inlet adapter connected to the nitrogen supply, and septum. The flask

was purged with nitrogen, immersed in an ice-acetone bath, and lithium

aluminum hydride solution in tetrahydrofuran (1.0 molar, 800 mL, 0.80 mol,

Aldrich) was added via cannula. Dry tetrahydrofuran (2x15 mL) was used to

rinse in the lithium aluminum hydride solution. When the solution had cooled to

0°C, the slurry of (±)-cis-4-amino-2-cyclopentene-l -carboxylic acid

4-toluenesulfonate salt in tetrahydrofuran was cannulated in with good stirring,

at such a rate as to keep the temperature less than 10°C and moderate the

hydrogen evolution (about one hour). The flask was rinsed with dry

tetrahydrofuran (2x15 mL), and the septum was replaced with a reflux

condenser. The resulting clear, light amber solution was slowly warmed to a

gentle reflux over the course of two hours, at which point it became cloudy.

After refluxing overnight (16 hours), the heating bath was dropped, sodium

fluoride (136.3 g, 3.25 mol, reagent grade powder) was added, and the condenser

reset for downward distillation. The mixture was distilled to a thin slurry

(700 mL of distillate collected), then cooled in an ice bath. Diethyl ether (dry,

500 mL) was added, and the condenser was replaced by an addition funnel

containing water (43 mL, 2.4 mol). The water was added very slowly

(two hours), with care taken to control the rate of hydrogen evolution and

maintain the temperature at 10±5°C. Meanwhile, water (54 mL) was added to

the above recovered distillate, and sufficient additional tetrahydrofuran was

added to bring the total volume to 900 mL (6% H2O). The reaction mixture was

filtered by suction, and the cake displace-washed with tetrahydrofuran (100 mL).

Part of the 6% water-tetrahydrofuran solution (300 mL) was used to slurry- wash

the cake, which was then returned to the reaction flask. The cake was triturated

(25 minutes) in 6% water-tetrahydrofuran (400 mL), filtered, and

displace-washed with 6% water-tetrahydrofuran (200 mL). The combined

filtrates were concentrated to a pale yellow oil under vacuum (44.07 g, 67.8% by

HPLC, see Example 3). This oil, containing pure title compound, water, and a

trace of tosylate salt, darkens rapidly under ambient conditions. It was immediately reacted to form the N-BOC derivative, a stable, crystalline solid,

(see the following Example). The filter cake was returned to the flask and triturated in methanol (800 mL) for 48 hours. The resulting slurry was filtered

under a rubber dam, and the cake was washed with methanol (200 mL). The filtrate was concentrated under vacuum to a yellow solid (56.80 g, 20.9% yield

by HPLC; total overall yield 88.7%).

Example 13

(-t)-cis-4- Amino-2-cvclopentene- 1 -methanol

By the method of Example 12 but on about twice the scale (97.40 g, 0.8924 mol

of (±)-2-azabicyclo[2.2.1] hept-5-en-3-one) the title compound was obtained as

extracts containing the title compound (0.7926 mol, 88.8% of theoretical, allowing for aliquots removed, as determined by the method of Example 11).

Example 14

(±)-cis-tert-Butyl N-(4-[hydroxymethyl)-2-cyclopenten-l-yl] carbamate

The combined tetrahydrofuran extracts from the preceding Example were

concentrated under vacuum to 1031 g, cooled in an ice-water bath, and a mixture

of sodium bicarbonate (97.46 g, 1.16 mol) in water (500 mL) was added. This

was followed by di-tert-butyl dicarbonate (204.5 g), 0.9501 mol). The mixture

was stirred at 5°C for two days. The methanol extracts from the preceding

Example were evaporated to an oily solid (136.64 g), which was added to the

mixture. After warming to room temperature, the organic solvents were

evaporated under vacuum, and the resulting slurry was extracted with hexanes,

three portions of methylene chloride, then hexanes again (200 mL each). The

organic extracts were evaporated to an oil, which was crystallized from hexanes

(about 300 mL), giving the title compound (154.15 g, 0.7229 mol). Additional

product was obtained by chromatography of the mother liquors (10.5 g,

0.0491 mol, 86.6% of theoretical from the starting lactam, allowing for aliquots

removed).

Example 15

(±)-cis-f4-(4.5-Dichloro-2-nitroanilino)-2-cvclopenten-l -vllmethanol

(±)-cis-tert-Butyl N-[4-(hydroxymethyl)-2-cyclopenten-l -yl]carbamate

(50.0 g, 0.230 mole) was stirred in 25% trifluoroacetic acid in methylene

chloride (1.5 L) at 0° C for 1.0 hour. Evaporation of volatiles left the

trifluroacetic acid salt of the amine described in Example 27 as a dark oil. To

this oil were added t-butanol (350 mL), potassium carbonate (65 g), and 1,2,4-

trichloro-5-nitrobenzene (Aldrich, 54.7 g, 0.230 mole as 97%). The resulting

mixture was refluxed with vigorous stirring for 3 days. Volatiles were removed

under vacuum and the residue triturated with methanol. The methanol-soluble

material was chromatographed on silica gel. C de product was eluted with 2%

methanol-chloroform to give orange solid (38.0 g). Crystallization from ethyl

acetate-hexanes gave title compound as orange crystals (34.0 g, 49%), m.p. 96-

98° C; ¹ H-NMR(DMSO-d6) and mass spectrum(CI) consistent with structure

and identical with samples of chiral enantiomers described in Examples 18 and

26.

Anal. Calcd. for C12H12N2CI2O3: C, 47.55; H, 3.99: N, 9.24 Cl, 23.39.

Found: C, 47.75; H, 4.10; N, 9.20; Cl, 23.52.

Continued elution of the column gave further fractions containing title

compound with minor low Rf impurities. These fractions were combined with

the mother liquor from the above crystallization and recrystallized from ethyl

acetate-hexanes to give additional orange solid (16.7 g) having identical ^H-

NMR spectrum and bringing the total yield to 73% .

Example 16

(±)-(lR*. 2S*. 3S*. 5S*)-3-(Acetoxymethyl)-5-(4.5-dichloro-2-nitroanilino)-

1.2-cvclopentanedivl diacetate and (±)(1R*. 2S*. 3R*. 5R»)-3-

(acetoxvmethvl)-5-(4.5-dichloro-2-nitroanilino)- 1.2-cvclopentanedivl diacetate

To a solution of (±)-cis-[4-(4,5-dichloro-2-nitroanilino)-2-cyclopenten-l-

yljmethanol (20.0 g, 66.0 mmol) and N-methylmorpholine N-oxide (Aldrich,

60% aqueous solution, 12.0 mL, 69 mmol) in acetone (280 mL) was added

osmium tetroxide (2.5% in t-butyl alcohol, Aldrich, 1.24 mL). After stirring at

ambient temperature for 18 hours, volatiles were removed in vacuo and the

residue stirred with pyridine (200 mL)-acetic anhydride ( 40 mL) for an

additional 18 hours. The solution was concentrated to a thick red oil which was

partitioned between saturated aqueous sodium carbonate and chloroform. The

chloroform layer was dried (sodium sulfate) and then concentrated to an oil in

vacuo. A mixture of the isomeric title compounds was eluted from a silica gel

column with 2% methanol-chloroform and crystallized from ethyl acetate-

hexanes (with seeding by crystals of the (lR*,2S*)-isomer prepared by the

method of Example 1) to give (±)-(lR*, 2S*, 3S*, 5S*)-3-(acetoxymethyl)-5-

(4,5-dichloro-2-nitroanilino)-l,2-cyclopentanediyl diacetate as orange crystals

(17.4 g, 57%), m.p. 154-156° C; ^! H-NMR(DMSO-d6) identical to that of the sample described in Example 1.

Continued crystallization of the mother liquor contents from ethyl acetate-

hexanes gave (±)(1R*, 2S*, 3R*, 5R*)-3-(acetoxymethyl)-5-(4,5-dichloro-2-

nitroanilino)-l,2-cyclopentanediyl diacetate as orange crystals (8.82 g, 29%),

m.p. 105-107° C; ^-NMRfDMSO-dό) _. .

Anal. Calcd. for C18H2ON2CI2O8: C, 46.67; H, 4.35; N, 6.05; Cl, 15.31.

Found: C, 46.50; H, 4.33; N, 5.96; Cl, 15.23.

Example 17

(±)(1R*. 2S*. 3R*. 5R*)-3-(Acetoxymethyl)-5-(2-bromo-5.6-dichloro-lH-

benzimidazol- 1 -vl)- 1.2-cvclopentanedi vl diacetate

(±)(1R*, 2S*, 3R*, 5R*)-3-(Acetoxymethyl)-5-(4,5-dichloro-2-nitroanilino)-l,2-

cyclopentanediyl diacetate (5.00 g, 10.8 mmol) was stirred in ammonia /

methanol (ca. 2 N, 100 mL) at ambient temperature for 18 hours. Evaporation of

volatiles in vacuo left residual orange solid (±)-(lR*, 2S*, 3R*, 5R*)-5-(4,5-

dichloro-2-nitroanilino)-3-(hydroxymethyl)- 1 ,2-cyclopentanediol having an

identical Rf on silica gel TLC plates to that of the chiral sample described in

Example 19. This solid was reduced with Raney nickel/ hydrogen(45 psi) in

isopropanol (200 mL). Catalyst was filtered off with Celite. The filtrate-wash

was evaporated to dryness in vacuo. The residue was refluxed in formic acid

(96%, 50 mL) for one hour, as described in Example 2. The oil remaining on

evaporation of the formic acid was dissolved in methanol. The pH was adjusted

to 13 with aqueous 5 N sodium hydroxide and the solution was stirred at

ambient temperature for one hour to hydrolyze formate esters. The pH was

adjusted to 7 with 1 N hydrochloric acid and volatiles removed by evaporation

in vacuo. Pyridine (100 mL) and acetic anhydride (4 mL) were added to the

residue and the mixture stirred at ambient temperature overnight. Evaporation of

volatiles in vacuo followed by chromatography on silica gel with 1% methanol-

chloroform gave (±)(1R*, 2S*, 3R*, 5R*)-3-(acetoxymethyl)-5-(5,6-dichloro-

lH-benzimidazol-l-yl)-l,2-cyclopentanediyl diacetate as white crystals from

ethanol-water (2.6 g, 53%), ¹ H-NMR(DMSO-d6) consistent with structure.

(±)(1R*, 2S*, 3R*, 5R*)-3-(Acetoxymethyl)-5-(5,6-dichloro-lH-benzimidazol-

l-yl)-l,2-cyclopentanediyl diacetate (2.5 g, 5.7 mmol) was dissolved in dry

dioxane (15 mL) and the solution refluxed while freshly recrystallized N-

bromosuccinimide (2.10 g, 1 1.5 mmol) was added all at once. After 5 minutes of

reflux, the red-brown solution was evaporated in vacuo to a red oil. A

chloroform solution of this oil was washed with water and then dried (sodium

sulfate). The chloroform solution was concentrated to an oil which was

chromatographed on silica gel. Product-containing fractions were eluted with 2-

4% methanol-chloroform. Crystallization from ethyl acetate-hexanes gave as

off-white solid (1.5 g, 50%); ¹ H-NMR(DMSO-d6)consistent with structure of

title compound. Such a sample was rechromatographed on silica gel with

elution by chloroform to give (±)(1R*, 2S*, 3R*, 5R*)-3-(acetoxymethyl)-5-(2-

bromo-5 ,6-dichloro- 1 H-benzimidazol- 1 -y 1)- 1 ,2-cyclopentanediyl diacetate as

white crystals, after crystallization from ethyl acetate-hexanes, m.p. 166-167° C;

¹ H-NMR(DMSO-d6)δ: 8.14 and 7.96 (both s, 1 each, 2 aromatic CH), 5.6-5.35

(m, 3, 2 OCH and NCH), 4.4-4.1 (m, 2, OCH2), 2.8-2.4 (m overlapping solvent,

2 CH), 2.4-2.1 (m overlapping s at 2.25, total 4, CH and CH3), 2.04 (s, 3, CH3),

1.37 (s, 1, CH3); mass spectrum(CI): 525(53), 523(100), 521(54, M+l).

Anal. Calcd for Ci9Hι9N2BrCl2θ6: C, 43.70; H, 3.67; N, 5.37; total halogen

as Cl, 20.37. Found: C, 43.65; H, 3.68; N, 5.35; total halogen as Cl, 20.32.

Example 18

(IS. 4R)-[4-(4.5-Dichloro-2-nitroanilino)-2-cvclopenten-l -vllmethanol

(-)-(lR, 4S)-tert-Butyl N-[4-hydroxymethyl)-2-cyclopenten-l-yl]

carbamate (15.00 g, 70.3 mmol) was converted by the method of Example 1 to

(IS, 4R)-[4-(4,5-dichloro-2-nitroanilino)-2-cyclopenten- 1 -yljmethanol, isolated

as a yellow powder after elution from a silica gel column with 1 :1 hexanes-

chloroform and resolidification from ethyl acetate-hexanes (9.97 g, 47%), m.p.

94.5-96.5° C; lH-NMR(DMSO-d6)δ: 8.24 (s, 1, benzimidazole CH), 8.09 (d, J

= 8.1 Hz, 1, NH), 7.51 (s, 1, benzimidazole CH), 5.95 and 5.85 (both m, 2,

CH=CH), 4.9-4.7 (m overlapping t at 4.78, J = 5.1 Hz, total 2, CHN and OH),

3.4 (m, 2, CH2O), 2.80 (m, 1, CH), 2.6-2.4 (m overlapping solvent, CH), 1.5-

1.4 (m, 1, CH); mass spectrum(CI): 303 (M+l); [a] ² <>589 +199° , [a]20 ₅₇ 8

+222° , [a] ²⁰ 546 +333° (c = 0.267, methanol).

ΔnaL Calcd. for C12H12N2CI2O3 O.I8 C6Hι;4: C, 49.30; H, 4.59; N,

8.79; Cl, 22.25. Found: C, 49.64; H, 4.64; N, 8.68; Cl, 22.10.

Example 19

(IS. 2R. 3R. 5R)-5-(4.5- Dichloro-2-nitro _a nilino)-3-rhvdroxvmethvl)-1.2-

cvclopentanediol and (IR. 2S. 3R. 5R)-5-(4.5- dichloro-2-nitroanilino)-3-

(hvdroxvmethvl)- 1.2-cvclopentanediol

To a solution of (IS, 4R)-[4-(4,5-dichloro-2-nitroanilino)-2-cyclopenten-

l-yl]methanol (8.60 g, 27.6 mmol) and N-methylmorpholine N-oxide (Aldrich,

60% aqueous solution, 5.02 mL, 29.0 mmol) in acetone (90 mL) was added

osmium tetroxide (Aldrich, 2.5% in t-butyl alcohol, 0.51 mL). After stirring at

ambient temperature for 18 hours, an additional 0.25 mL of 60% aqueous N-

methylmorpholine N-oxide was added and the solution stirred for an additional 5

hours. Volatiles were evaporated in vacuo and the residue recrystallized twice

from 95% ethanol to give (IS, 2R, 3R, 5R)-5-(4,5- dichloro-2-nitroanilino)-3-

(hydroxymethyl)-l,2-cyclopentanediol as yellow powder (1.78 g, 19%), m.p.

197-199° C; ¹ H-NMR(DMSO-d6)δ: 8.23 (s, 1, benzimidazole CH), 8.1 (d, J =

7.0 Hz, 1, NH), 7.50 (s, 1, benzimidazole CH), 5.02 (d, J = 4.9 Hz, 1, OH), 4.74

(t, J = 5.1 Hz, 1, CH2OH), 4.58 (d, J = 5.1 Hz, 1, OH), 4.0-3.8 (m, 1, NCH), 3.8-

3.7 (m, 2, 2 OCH), 3.5-3.4 (m, 2, CH2O), 2.45-2.25 ( m, 1, CH), 2.1-1.9 (m, 1,

CH), 1.4-1.2 (m, 1, CH); mass spectrum(CI): 337 (M+l); [α] ²⁰ 589 -106° ,

[α] ²⁰ 578 -118° , [α] ² ^ -182° (c = 0.273, methanol).

Anal- Calcd. for C12H14N2CI2Q5: C, 42.75; H, 4.19; N, 8.31; Cl, 21.03.

Found: C, 42.84; H, 4.21; N, 8.24; Cl, 21.09.

Chromatography of the mother liquor contents on silica gel gave the (IR,

2S)- isomer on elution with 7-8% methanol-chloroform; two resolidifications

from 90% ethanol gave (IR, 2S, 3R, 5R)-5-(4,5- dichloro-2-nitroanilino)-3-

(hydroxymethyl)-l,2-cyclopentanediol as a yellow powder (1.57 g, 17%), m.p.

179-181 ° C; !H-NMR(DMSO-d6)δ: 8.70 (d, J = 7.1 Hz, 1, NH), 8.22 and 7.32

(both s, 1 each, 2 benzimidazole CH), 5.28 (d, J = 5.6 Hz, 1, OH), 4.77 (d, J =

3.9 Hz, 1 OH), 4.45 (t, J = 4.9 Hz, 1, CH2OH), 4.1-3.9 (m, 3, 2 OCH and NCH),

3.6-3.5 and 3.45-3.35 (both m partially overlapping H2O, 2, CH2O), 2.45-2.25

(m, 1, CH), 2.1-3.9 (m, 1, CH), 1.35-1.25 (m,l , CH); mass spectrum(CI):

337(M+1 ); [α] ⁰ 589 -15.6° , [α] *^ -13.2° , [α] ²⁰ 546 -4.00° (c = 0.250,

methanol).

Anal. Calcd. for C12H14N2CI2O5: C, 42.75; H, 4.19; N, 8.31 ; Cl, 21.03.

Found: C, 42.87; H, 4.15; N, 8.30; Cl, 21.14.

Elution with 8-10% methanol-chloroform gave white solid (2.9 g) which

iH-NMR showed to be an approximately 1 :1 mixture of the two isomers.

Continued elution of the column with 10-20% methanol-chloroform gave

fractions containing additional (IS, 2R, 3R, 5R)-5-(4,5- dichloro-2-nitroanilino)-

3-(hydroxymethyl)-l,2-cyclopentanediol which solidified from 90% ethanol to

white powder (2.23 g) bringing the total yield of this isomer to 43%.

Example 20

(IS. 2R. 3R. 5R)-3-(Acetoxvmethvl)-5-(4.5-dichloro-2-nitroanilino)-1.2-

cvclopentanedivl diacetate

(IS, 4R)-[4-(4,5-Dichloro-2-nitroanilino)-2-cyclopenten- 1 -yljmethanol (

3.75 g, 11.1 mmol) was acetylated in pyridine-acetic anhydride as in Example

16. The crude product was eluted from a silica gel column with 2% methanol-

chloroform and solidified from ethyl acetate to give (IS, 2R, 3R, 5R)-3-

(acetoxymethyl)-5-(4,5-dichloro-2-nitroanilino)- 1 ,2-cyclopentanediyl diacetate

as yellow powder (5.13 g, 100%), NMR identical to that of Example 1. Such a

sample was crystallized from ethyl acetate-hexanes to give title compound as

yellow powder , m.p. 128-130° C; ¹ H-NMR(DMSO-d6) and mass spectrum

(CI) identical to those of Example 1.; [α] ²⁰ 589 -95.8° , [α] ²⁰ 578 -107° ,

[α] ²⁰ 546 -165° (c = 0.259, methanol).

Δna Calcd. for C18H2ON2CI2O8: C, 46.67; H, 4.35; N, 6.05; Cl, 15.31.

Found: C, 46.74; H, 4.36; N, 5.96; Cl, 15.38.

Example 21

(IS. 2R. 3R. 5R)-3-(Acetoxvmethvl)-5-(5.6-dichloro-lH-benzimidazol-l-vl)-

L2-cvclopentanedivl diacetate

(IS, 2R, 3R, 5R)-3-(Acetoxymethyl)-5-(4,5-dichloro-2-nitroanilino)-l,2-

cyclopentanediyl diacetate (4.42 g, 9.97 mmol) was converted to title compound

as with the racemic sample described in Example 2. Crude product was

chromatographed on silica gel with elution by 5% methanol-chloroform and

solvents evaporated to give (IS, 2R, 3R, 5R)-3-(acetoxymethyl)-5-(5,6-dichloro-

lH-benzimidazol-l-yl)-l,2-cyclopentanediyl diacetate as an off-white solid

foam from ethanol (4.0 g, 90%); ¹ H-NMR(DMSO-d6) and mass spectrum(CI)

identical to those of racemate described in Example 2; [α] ² ^5 9 +25.5°,

[α] ²⁰ 578 + ² 6.7° , [α] ⁰ 546 +30.6° (c = 0.255, methanol).

Anal. Calcd. for C19H2ON2CI2O6: C, 51.49; H, 4.55; N, 6.32; Cl, 16.00.

Found: C, 51.33; H, 4.58; N, 16.27; Cl, 15.90.

Example 22

(IS. 2R. 3R. 5R)-5-(5.6-Dichloro-lH-benzimidazoI-l-vl)-3-(hvdroxvmethvl)-

1.2-cvclopentanediol

(IS, 2R, 3R, 5R)-3-(Acetoxymethyl)-5-(5,6-dichloro-lH-benzimidazol-

l-yl)-l,2-cyclopentanediyl diacetate (0.96 g, 2.17 mmol) and sodium carbonate

(0.230 g, 2.17 mmol) were stirred in water (3 mL)-ethanol(15 mL)-methanol(15

mL) at ambient temperature for 24 hours. The pH was adjusted to 7 with acetic

acid and the volatiles removed in vacuo. The residual solid was slurried in water

(25 mL) and filtered. Resolidifϊcation from 2:1 ethanol-methanol gave (IS, 2R,

3R, 5R)-5-(5,6-dichloro- 1 H-benzimidazol- 1 -yl)-3-(hydroxymethyl)- 1 ,2-

cyclopentanediol as white powder (408 mg, 60%), m.p. 222-225° C; *H-

NMR(DMSO-d6)δ: 8.49, 8.09, and 7.96 (all s, 1 each, 3 benzimidazole CH),

5.04 (d, J = 7.0 Hz, 1, OH), 4.87 (t, J = 5.1 Hz, 1, CH2OH), 4.8-4.6 (m

overlapping d at 4.76, J = 4.3 Hz, 2, NCH and OH), 4.25-4.10 (m, 1, OCH), 3.9-

3.8 (m, 1, OCH), 3.6-3.45 (m, 2, CH2O), 2.45-2.25 (m, 1, CH), 2.2-2.0 (m, 1,

CH), 1.85-1.65 (m, 1, CH); mass spectrum(CI): 317 (M+l); [α] ²⁰ 589 -l ² - ² ° ,

[α] ²⁰ 578 -l ² - ° , [α] ²⁰ 546 -14.1 ° (c = 0.255, methanol).

Anal. Calcd. for C13H14N2CI2O3: C, 49.23; H, 4.45; N, 8.83; Cl, 22.36.

Found: C, 49.25; H, 4.47; N, 8.83; Cl. 22.46.

Example 23

(IS. 2R. 3R. 5R)-5-(2-Bromo-5.6-dichloro-l H-benzimidazol- 1 -

vl)-3-(hvdroxvmethvl)-1.2-cvclopentanediol

(IS, 2R, 3R, 5R)-3-(Acetoxymethyl)-5-(5,6-dichloro-lH-benzimidazol-

l-yl)-l,2-cyclopentanediyl diacetate (2.00 g, 4.51 mmol) was dissolved in dry

N.N-dimethylformamide (9 mL) and heated to 90°C. N-bromosuccinimide (1.62

g, 9.02 mmol) was added in four portions over 5 hours. . Volatiles were

evaporated in vacuo. The residue was chromatographed on silica gel and product

was eluted with 30-50% ethyl acetate-hexanes as a yellow glass (1.00 g, 43%);

*H-NMR(DMSO-d6) consistent with stmcture. This sample was deblocked with

sodium carbonate (203 mg, 1.9 mmol) in water (3 mL)-ethanol(15 mL)-

methanol(l 5 mL) at ambient temperature for 5 hours. The pH was adjusted to 7

with acetic acid. The solution was evaporated to dryness in vacuo and the

residue was triturated with water to give white powder which was

chromatographed. Elution of a silica gel column with 10-12% methanol-

chloroform gave (IS, 2R, 3R, 5R)-5-(2-bromo-5,6-dichloro-lH-

benzimidazol-l-yl)-3-(hydroxymethyl)-l,2-cyclopentanediol as white powder

after solidification from 1 :1 ethanol-methanol (410 mg, 54%), m.p. 212-215°C;

1 H-NMR(DMSO-d6) and mass spectrum identical with those of racemate

described in Example 4; [α] ²⁰ 589 -31.2° , [α] ⁰ 578 -32.3° , [α] ²⁰ 546 -37.3° (c = 0.260, methanol).

ΔnaL Calcd. for Ci3Hι3N2BrCl2θ3: C, 39.43; H, 3.31 ; N, 7.07; total

halogen as Cl, 26.86. Found: C, 39.62; H, 3.37; N, 7.02; total halogen as Cl,

26.75.

Example 24

(IS, 2R, 3R, 5R)-5-[5,6-Dichloro-2-(cyclopropylamino)-lH-benzimidazol-l-y l]-

3-(hydroxymethyl)- 1 ,2-cyclopentanediol

(IS, 2R, 3R, 5R)-3-Acetoxymethyl)-5-(2-bromo-5,6-dichloro-l-H-

benzimidazol-l-yl)-l,2-cyclopentanediyl diacetate (500 mg 0.958 mmole) was

refluxed in water:ethanol/2:l (7.5 mL) with cyclopropylamine (0.66 mL, 9.6

mmole) under nitrogen for 18 hours. TLC (silica gel, 10% methanol-chloroform)

showed complete conversion to a single spot with lower R _f than starting

material. 1 N sodium hydroxide (0.96 mL) was added and volatiles were

evaporated. The residue was chromatographed on a silica gel flash column.

Title compound was eluted with 10% methanol-chloroform as a colorless glass

which solidified from water.ethanol/ 2: 1 (5 mL) to give off-white powder (207

mg, 59%, m.p. 1 16-1 18°C dec; Η-NMR(DMSO-d ₆ )δ and mass spectrum:

identical with those of enantiomer described in Example 74; [α] ²⁰ ₅₈₉ -12.2°,

[α] ²⁰ _57g -12.5°, [α] ²⁰ ₅₄₆ -13.5° (c = 0.312, methanol).

Anal.Calcd. For C ₁₆ H ₁₉ N ₃ C ₁₂ O ₃ : C, 51.63; H, 5.15: N, 11.29; Cl, 19.05.

Found: C, 51.37; H, 5.10; N, 11.16; Cl, 19.25.

Example 25

(1 R. 4S)-4-Amino-2-cvclopentene-l -methanol

A mixture of (-)-(lS, 4R)-4-amino-2-cyclopentene-l -carboxylic acid (

Chiroscience Ltd., Cambridge, England; 40.00 g, 0.315 mole) in dry

tetrahydrofuran (300 mL) was stirred in an ice bath while 1 M lithium

aluminum hydride in tetrahydrofuran (Aldrich, 485 mL) was added over 1.5

hours. The temperature during this addition was not allowed to exceed 0° C.

The mixture was brought to ambient temperature and then to reflux over one

hour and maintained at reflux for 2.5 hours. The mixture was allowed to cool to

ambient temperature and sodium fluoride (89.6 g) was added and stirring

continued for an additional 0.5 hour. The mixture was cooled (ice bath) and

water (23 mL) added slowly. Stirring was continued for an additional 0.5 hour.

The precipitate was filtered and extracted with 40% methanol-tetrahydrofuran (

2x300 mL). The filtrate-wash was concentrated in vacuo to a colorless oil which

darkened rapidly in air and light and was used immediately (Example 16). Such

a sample was dried at ambient temperature / 0.2 mm Hg to a pale yellow oil;

^H-NMR(DMSO-d6) identical to that of the enantiomer described in Example

22, d: 5.67 (m, 2, CH=CH), 3.8-3.7 (m, 1, CHN), 3.32 (d, J = 6.0 Hz,

overlapped by broad D2θ-exchangeable peak centered at 3.18, CH2O, OH,

NH2 and H2O in solvent), 2.68-2.56 (m, 1, H-l), 2.28-2.18 (m, 1, 2 CH2),

1.08-0.98 (m, 1, 1/2 CH2); mass spectrum(CI): 114(M+1); [α] ²⁰ 589 +55.0° ,

[α] ²⁰ 578 +58.3° , [a] ² "546 +67.4° , [a] ²⁰ 436+l 19° (c = 0.242, methanol).

Δnal- Calcd. for CόHj 1NO 0.31 H2O: C, 60.69; H, 9.86; N, 11.80.

Found: 61.12; H, 9.79; N, 11.38.

Example 26

(lR. 4S)-[4-(4.5-Dichloro-2-nitroanilino)-2-cvclopenten-l-vllmeth anol

The filtrate-wash from Example 25 was concentrated and t-butanol (400

mL) was added to the residual oil. This solution was used for the condensation

with l,2,4-trichloro-5-nitrobenzene (Aldrich, 71.3 g, 0.315 mole as 97%) by the

method of Example 10. The reaction mixture, after evaporation of volatiles in

vacuo, was chromatographed on a silica gel column eluted with 1 : 1 hexanes-

ethyl acetate and ethyl acetate. Rechromatography of the cmde product on silica

gel was carried out with elution of by 4-6% methanol-chloroform. Combined

product-containing fractions yielded 58 grams of reddish solid on evaporation

of solvents. This solid was resolidified from ethyl acetate-hexanes to give (IR,

4S)-[4-(4,5-dichloro-2-nitroanilino)-2-cyclopenten- 1 -yljmethanol as yellow

powder (34.5 g, 36% from (-)-(lS, 4R)-4-amino-2-cyclopentene-l -carboxylic

acid); m.p. 95-97° C; ¹ H-NMR(DMSO-d6) and mass spectrum(CI) identical

with those of the enantiomer described in Example 18; [α] ² ^589 -195° ,

[α] ²⁰ 578 - ² 1 ° , [α] ² <>546 -326° (c = 0.350, methanol).

Anal. Calcd. for C12H12N2CI2O3: C, 47.55; H, 3.99; N, 9.24; Cl, 23.39.

Found: C, 47.56; H, 4.01; N, 9.25; Cl, 23.30.

Continued elution of the column (above) gave additional yellow powder

(18.0 g, 19%) which 1-NMR showed to be additional title compound

contaminated by ca. 15% of (IR, 4S)-[4-(2,5-dichloro-4-nitroanilino)-2-

cyclopenten- 1 -yljmethanol.

Example 27

(IR. 2S. 3S. 5S)-3-(Acetoxymethyl)-5-(4.5-dichloro-2-nitroanilino)-1.2-

cvclopentanedivl diacetate and (IS. 2R. 3S. 5S)-3-(acetoxvmethvl)-5-(4.5-

dichloro-2-nitroanilino)-l .2-cvclopentanedivl diacetate

( 1 R, 4S)-[4-(4,5-Dichloro-2-nitroanilino)-2-cyclopenten- 1 -yljmethanol

(17.00 g, 56.1 mmol) was hydroxylated and the mixture of triols was acetylated

as in Example 16. The cmde red oil isolated after acetylation was

chromatographed on silica gel and a mixture of title compounds eluted with 2%

methanol-chloroform. Fractional crystallization from ethyl acetate-hexanes gave

(IR, 2S, 3S, 5S)-3-(acetoxymethyl)-5-(4,5-dichloro-2-nitroanilino)-l,2-

cyclopentanediyl diacetate as yellow needles in two crops (12.78 g, 49%), m.p.

127-128° C; ¹ H-NMR(DMSO-d6) and mass spectrum (CI) identical to those of

the racemic sample described in Example 1 and the enantiomer described in

Example 55; [α] ²⁰ 589 +106° , [α] ²⁰ 578 +119° , [α] ² 0s46 +184 ^o (c = 0.275,

methanol).

Anal- Calcd. for C18H2ON2CI2O8: C, 46.67; H, 4.35; N, 6.05; Cl, 15.31.

Found: C, 46.74; H, 4.40; N, 6.09; Cl, 15.22.

Continued fractional crystallization of the mother liquor contents from

ethyl acetate-hexanes gave (IS, 2R, 3S, 5S)-3-(acetoxymethyl)-5-(4,5-dichloro-

2-nitroanilino)-l,2-cyclopentanediyl diacetate as orange crystals (2.45 g, 10%),

m.p. 122-124° C; lH-NMR(DMSO-dό).

Evaporation of combined mother liquors gave an additional 9.50 g (40%)

of an approximately 1 : 1 (by ^H-NMR) mixture of the title compounds.

Example 28

(IR. 2S. 3S. 5S)-3-(Acetoxymethyl)-5-(5.6-dichloro-1 H-benzimidazol-1 -vl)-1.2-

cvclopentanedivl diacetate

(IR, 2S, 3S, 5S)-3-(Acetoxymethyl)-5-(4,5-dichloro-2-niuOanilino)-l,2-

cyclopentanediyl diacetate was converted to title compound as in Example 2.

The cmde product after formic acid treatment was chromatographed on silica gel

with elution by 10% ethyl acetate-hexanes. Evaporation of product-containing

fractions left (IR, 2S, 3S, 5S)-3-(acetoxymethyl)-5-(5,6-dichloro-lH-

benzimidazol-l-yl)-l,2-cyclopentanediyl diacetate as a white solid foam from

ethyl acetate (1.85 g, 95%); ¹ H-NMR(DMSO-d6) and mass spectrum(CI)

identical to those of racemate described in Example 2 and enantiomer described

in Example 56; [α] ²⁰ 589 -25.5° , [α] ²⁰ 578 -27.0° , [α] ²⁰ 546 -31.2 (c = 0.333,

methanol).

Anal. Calcd. for C19H2ON2CI2O6 O.I EtOAc: C, 51.54; H, 4.64; N,

6.20; Cl, 15.68. Found: C, 51.29; H, 4.69; N, 6.19; Cl, 15.91.

Example 29

(I S. 2R. 3S. 5S)-5-(5.6-Dichloro-l H-benzimidazol- 1 -yl)-3-(hvdroxymethyl)-

1.2-cvclopentanediol and (IR. 2S. 3S. 5S)-5-(5.6-Dichloro-lH-benzimidazol-l-

vl)-3-(hvdroxvmethvl)-1.2-cvclopentanediol

An ca. 1:1 mixture of (IR, 2S, 3S, 5S)-3-(acetoxymethyl)-5-(4,5-

dichloro-2-nitroanilino)-l,2-cyclopentanediyl diacetate and (IS, 2R, 3S, 5S)-3-

(acetoxymethyl)-5-(4,5-dichloro-2-nitroanilino)- 1 ,2-cyclopentanediyl diacetate

(4.30 g, 9.28 mmol) was deacetylated with sodium carbonate (97 mg) in 1 :1 :1

water-ethanol-methanol (100 mL) at ambient temperature for 24 hours. The pH

was adjusted to 7 with acetic acid and the volatiles removed in vacuo. The

residual solid was extracted with methanol. The methanol filtrate was

evaporated to dryness in vacuo. The residual solid was dissolved in ethanol (55

mL)- water (20 mL), adjusted to pH 5-6 with sulfuric acid, and refluxed with iron

powder (325 mesh, 99.9%, Aldrich, 5.18 g, 93 mequiv) and iron(II) sulfate

heptahydrate (Aldrich, 98+%, 1.30 g, 4.58 mequiv) for 4 hours. Solids were

filtered off and the ethanol filtrate- wash concentrated to an oil.

Triethylorthoformate (55 mL) and methanesulfonic acid (0.05 mL) were added

to the oil and the resulting solution stirred at ambient temperature for 18 hours.

Concentration in vacuo left an oil which was redissolved in 1 N hydrochloric

acid (50 mL)-dioxane(5 mL). After 2.5 hours, the pH was adjusted to 7 with 1 N

sodium hydroxide and the volatiles evaporated in vacuo. The residual solids

were chromatographed on silica gel. Elution with 10-12% methanol-chloroform

gave fractions containing (I S, 2R, 3S, 5S)-5-(5,6-dichloro-lH-benzimidazol-l-

yl)-3-(hydroxymethyl)-l,2-cyclopentanediol, which was isolated as white

crystals (540 mg, 18%) after crystallization from ethyl acetate-hexanes, m.p.

201-202° C; ¹ H-NMR(DMSO-d6)d: 8.42, 8.07, and 7.92 (all s, 1 each, 3

benzimidazole CH), 5.1-4.8 (m overlapping d at 5.02, J = 5.7 Hz, and d at 4.93, J

= 3.9 Hz, total 3, NCH and 2 OH), 4.54 (t , J = 4.8 Hz, 1 , OH), 4.2-4.0 (m, 2, 2

OCH), 3.75-3.45 (m, 2, OCH2), 2.4-1.9 (m, 3, CH2 and CH); mass

spectrum(CI): 317 (M+l); [α] ²⁰ 589 -61.4° , [α] ²⁰ 578 -63.1 ° , [α] ² ^ -72.9° (c = 0.350, methanol).

Anal- Calcd. for C13H14N2CI2O3: C, 49.23; H, 4.45; N, 8.83; Cl, 22.36.

Found: C, 49.20; H, 4.45; N, 8.78; Cl, 22.37.

Continued elution of the column with 15-20% methanol-chloroform gave

fractions containing a mixture of the title compounds followed by fractions

containing only (IR, 2S, 3S, 5S)-5-(5,6-dichloro-lH-benzimidazol-l-yl)-3-

(hydroxymethyl)-l,2-cyclopentanediol, which was isolated as white crystals

(605 mg, 21%) on crystallization from 10% methanol-ethyl acetate, m.p. 221-

222° C; !H-NMR(DMSO-d6) and mass spectrum(CI) 317(M+1); [α] ²⁰ 589 +14.5° , [α] ²⁰ 578 +15.2° , [α] ²⁰ 546 +16.9° (c = 0.290, methanol).

Anal. Calcd. for C13H14N2CI2O3: C, 49.23; H, 4.45; N, 8.83; Cl, 22.36.

Found: C, 49.29; H, 4.46; N, 8.87; Cl, 22.26.

Example 30

(IR. 2S. 3S. 5S)-3-(Acetoxvmethvl)-5-(2-bromo-5.6-dichloro-l H-benzimidazol

- 1 -yl)- 1.2-cvclopentanediyl diacetate

(IR, 2S, 3S, 5S)-3-(Acetoxymethyl)-5-(5,6-dichloro-lH-benzimidazol-l-

yl)-l,2-cyclopentanediyl diacetate (1.40 g, 2.94 mmol) was brominated as in

Example 3. Volatiles were removed in vacuo and the residue chromatographed

on silica gel. Cmde product eluted with 20-30% hexane-ethyl acetate as a colorless oil. A chloroform solution of the oil was washed with water in order to

remove contaminating succinimide. The chloroform solution was dried (sodium

sulfate) and evaporated to dryness in vacuo to give title compound as white solid

foam from ethanol (760 mg, 50%); *H-NMR (DMSO-d.6) and mass spectrum(CI) identical to racemate described in Example 3; [α] ² ^5 9 +43.8° ,

[α] ²⁰ 578 +45.2° , [α] ²⁰ 546 52.2° (c = 0.345, methanol).

Anal Calcd. for Ci9Hι9N2BrCl2θ6 0.05 EtOH : C, 43.74; H, 3.71; N,

5.34; total halogen as Cl, 20.28. Found: C, 43.74; H, 3.69; N, 5.35; total

halogen as Cl, 20.41.

Example 31

(IR. 2S. 3S. 5S)-5-(2-Bromo-5.6-dichloro-lH-benzimidazol-l-yl)-3-

(hvdroxvmethvl)- 1.2-cvclopentanediol

(IR, 2S, 3S, 5S)-3-(Acetoxymethyl)-5-(5,6-dichloro-lH-benzimidazol-l-

yl)-l,2-cyclopentanediyl diacetate (660 mg, 1.26 mmol) was deacetylated as in

Example 4 to give title compound as white powder after solidification from 1 : 1

ethanol-methanol (415 mg, 83%), m.p. 213-216° C; !H-NMR(DMSO-d6) and

mass spectrum(CI) identical with those of racemate described in Example 4;

[α] ²⁰ 589 +35.9° , [α] ²⁰ 578 +36.8° , [α] ²⁰ 546 +42.1 ° (c = 0.340, methanol).

Anal- Calcd. for Ci 3Hι3N2BrC-2θ3: C, 39.43; H, 3.31; N, 7.07; total

halogen as

Cl, 26.86. Found: C, 39.48; H, 3.29; N, 7.00; total halogen as Cl, 26.90.

Example 32

(IR. 2S. 3S. 5S)-5-r5.6-Dichloro-2-(cvclopropvlamino)-lH-benzimidazol-l-v n-

3-(hvdroxvmethvl)- 1.2-cvclopentanediol

(IR, 2S, 3S, 5S)-3-(Acetoxymethyl)-5-(2-bromo-5,6-dichloro-lH-

benzimidazol-l-yl)-l,2-cyclopentanediyl diacetate (500 mg. 0.958 mmole) was

refluxed in wateπethanol/ 2:1 (7.5 mL) with cyclopropylamine (freshly opened

ampoule from Aldrich, 0.66 mL, 9.6 mmole) under nitrogen for 18 hours. TLC

(silica gel, 10% methanol-chloroform) showed complete conversion to a single

spot with lower Rf than starting material. 1 N sodium hydroxide (0.96 mL) was

added and volatiles were evaporated. The residue was chromatographed on a

silica gel flash column. Title compound was eluted with 10% methanol-

chloroform as a colorless glass which solidified from water: ethanol/ 2:1 (5 mL)

to give white powder (170 mg, 48%), m.p. 219-220°C; ¹ H-NMR(DMSO-d6)δ:

7.64 and 7.46 (both s, 2, aromatic CH), 7.11 (m, 1, NH), 5.11 (t, J = 4.3 Hz, 1,

OH), 4.77 (d, J = 7.0 Hz, 1, OH), 4.67 (d, J = 3.7 Hz, 1, OH), 4.65-4.30 (m, 2,

OCH and NCH), 3.85-3.75 (m, 1, OCH), 3.7-3.4 (m, 2, OCH2), 2.85-2.70 (m, 1,

NCH of cyclopropyl), 2.15-1.80 (m, 3, CH2 and CH of cyclopentane), 0.80-0.50

(m, 4, 2 CH2 of cyclopropyl); mass spectrum (CI): 372(M+1); [α] ²⁰ 589

+13.4°, [α] ²⁰ 578 +15.5°, [α] ²⁰ 546 +16.9° (c = 0.277, methanol). [See

Examples 26-28 and 30]

Anal. Calcd. for C16H19N3CI2O3: C, 51.63; H, 5.15: N, 11.29; Cl,

19.05. Found: C, 51.36; H, 5.06; N, 11.25; Cl, 19.16

Example 33

(IR. 2S. 3S. 5S)-5-[5.6-Dichloro-2-(isopropvlamino)-lH-benzimidazol-l-vll -3-

(hvdroxvmethvl)-1.2-cvclopentanediol

(IR, 2S, 3S, 5S)-3-(Acetoxymethyl)-5-(2-bromo-5,6-dichloro-lH-

benzimidazol-l-yl)-l,2-cyclopentanediyl diacetate (1.00 g, 1.92 mmole) was

refluxed in ethanol (10 mL) with isopropylamine (1.6 mL, Fluka) under nitrogen

for 24 hours. A second portion of isopropylamine (0.80 mL) was added and

reflux continued for an additional 4 hours. Volatiles were evaporated, the

residue was redissolved in ethanol, 1 N sodium hydroxide (1.90 mL) was added,

and volatiles were reevaporated. The residue was chromatographed on a silica

gel column. Title compound was eluted with 10% methanol-ethyl acetate as a

colorless glass. Concentration of an ethanol solution gave title compound as a

off-white solid foam (360 mg, 46%). Such a sample was solidified by trituration

with 95% water-5% methanol to give title compound as white powder (96%),

m.p. 137-138°C; ¹ H-NMR(DMSO-dό)δ 7.60 and 7.39 (both s, 2, aromatic

CH), 6.64 (d, J = 7.4 Hz, 1, NH), 5.14 (t, J = 4.3 Hz, 1, OH), 4.81 (d, J = 7.3 Hz,

1, OH), 4.70 (d, J = 3.5 Hz, 1, OH), 4.70-4.50 (m, 1, NCH), 4.50-4.30 (m, 1,

OCH), 4.10-4.00 (m, 1, NCH of cyclopropylamino), 3.9-3.75 (m, 1, OCH), 3.70-

3.50 (m, 2, OCH2), 2.20-1.80 (m, 3, CH2 and CH of cyclopentane), 1.24 (d, J =

6.6 Hz, 6, 2 CH3); mass spectrum (CI): 374(M+1); [α] ²⁰ 589 -3.72°, [α] ²⁰ 578 -

2.60°, [α] ²⁰ 546 - ² - 3°, [α] ²⁰ 436 -9.67°, [α] ²⁰ 365 -51.7° (c = 0.269, methanol).

[See Examples 16-18 and 20]

Anal. Calcd. for C]6H2lN3Cl2θ3-1.3 H2O: C, 48.32; H, 5.98; N, 10.57;

Cl, 17.83. Found: C, 48.08; H, 5.91; N, 10.41; Cl, 18.13.

Example 34

(±WIR*. 2S*. 3S*. SS^-S^.ό-Dichloro^- mino-lH-benzimidazol-l-vD-S-

(hvdroxvmethvl)- 1.2-cvclopentanediol

(±)(1R*, 2S*, 3S*, 5S*)-3-(Acetoxymethyl)-5-(2-bromo-5,6-dichloro-

1 H-benzimidazol- l-yl)-l,2-cyclopentanediyl diacetate (750 mg, 1.44 mmol) was

dissolved in ethanol (10 mL). Hydrazine hydrate (55%, 0.41 mL, 7.2 mmol)

was added and the solution was refluxed for 2 hours. Volatiles were evaporated

and the residual white solid was resolidified from ethanol-water and stirred with

Raney nickel (preequilibrated under hydrogen) in methoxyethanol (20 mL) for

30 minutes. Catalyst was filtered off and the filtrate made slightly basic with

aqueous sodium hydroxide to complete removal of the acetate groups. The

solution was neutralized, and volatiles evaporated. The residual solid was

recrystallized from ethanol-water to give title compound as pale pink solid (97

mg, 20%), m.p. 283-284°C dec; ¹ H-NMR(DMSO-d6)d: 7.61 and 7.30 (both s,

2, aromatic CH), 6.65 (br s, 2, NH2), 5.07 (t, J = 4.3 Hz, 1 , OH), 4.80 (d, J = 7.0

Hz, 1, OH), 4.66 (d, J = 3.7 Hz, 1, OH), 4.65-4.50 (m, 1 , NCH), 4.45-4.30 (m, 1,

OCH), 3.90-4.80 (m, 1, OCH), 3.70-3.40 (two m, 2, OCH2), 2.20-1.80 (m, 3,

CH2 and CH of cyclopentane); mass spectrum (CI): 332 (M+l). [See Examples

1-3]

Anal. Calcd. for C13H15N3CI2O3: C, 47.01; H, 4.55; N, 12.65; Cl,

21.35. Found: C, 46.72; H, 4.60; N, 12.46; Cl, 21.08.

Example 35

⁽ ±H1R*.2R*.

4S*)-2-f2-Cvclopropvlamino-5.6-dichloro-l H-benzimidazol- 1 -vl)-

4-(hydroxymethyl)cvclopentanol

(±)-(lR*, 2R*,

4S * )-4-( Acetoxymethyl)-2-(2-bromo-5,6-dichloro- 1 H-benzimidazol- 1 -yl)-

cyclopentyl acetate (500 mg, 1.50 mmol) was reacted with cyclopropylamine

(0.73 mL) in the manner of Example 32. Cmde product was chromatographed

on silica gel and title compound eluted with 5% methanol-ethyl acetate as a

colorless glass which solidified from ethyl acetate-hexanes to white powder (180

mg, 48%), m.p. 251 -253 °C; lH-NMR(DMSO-d6)δ: 7.54 and 7.45 (both s, 2,

aromatic CH), 5.04 (d, J = 5.1 Hz, 1, OH), 4.97 (t, J = 4.7 Hz, 1, OH), 4.60-4.50

and 4.50-4.30 (both m, 1 each, NCH and OCH), 3.50 (m, 2, OCH2), 2.80 (m, 1,

CH), 2.35-2.10 (m, 1, CH), 2.05-1.80 (m, 3, CH2 and CH of cyclopentane),

1.80-1.60 (m, 1, CH), 0.80-0.50 (1 m, 4, 2CH2 of cyclopropyl); mass spectrum

(CI): 356 (M+l). [See Examples 5-7]

Anal. Calcd. for C16H19N3CI2O2: C, 53.97; H, 5.34; N, 1 1.80; Cl,

19.91. Found: C, 53.72; H, 5.42; N, 11.52; Cl, 19.64.

Example 36

(±WIR*. 2S*. 3S*. 5S*)-5-r5.6-Dichloro-2-(cvclobutvlamino)-lH-

benzimidazol-l-vl]-3-(hvdroxvmethvl)-1.2-cvcIopentanediol

(±)(1R*, 2S*, 3S*, 5S*)-3-(Acetoxymethyl)-5-(2-bromo-5,6-dichloro-

1 H-benzimidazol- l-yl)-l,2-cyclopentanediyl diacetate (500 mg, 0.958 mmol)

was dissolved in absolute ethanol (7 mL) and cyclobutylamine (0.41 mL, 4.8

mmol) was added. The solution was refluxed under nitrogen for 18 hours.

Volatiles were evaporated and the residue stirred in methanol half-saturated with

ammonia at 0° C (20 mL) for 18 hours. Volatiles were removed in vacuo and the

residue crystallized from ethanol-water to give title compound as white solid,

m.p. 250° C dec; 1 H-NMR(DMSO-d6)δ 7.61 and 7.38 (both s, 1 each, aromatic

CH), 7.07 (d, J = 7.4 Hz, 1, NH), 5.15 (t, J = 3.9 Hz, 1, OH), 4.81 (d, J = 7.3 Hz,

1, OH), 4.71-4.45 (m overlapping d at 4.71, J = 3.5 Hz, total 2, OH and NCH),

4.40-4.30 (m, 2. OCH and NCH), 3.82-3.80 (m, 1, OCH), 3.72-3.42 (both m, 1

each, OCH2), 2.32-1.67 (three m, 9, 4CH2 and CH); mass spectrum (CI):

386(M+1). [See Examples 5-7]

Anal- Calcd. for Ci7H2lN3Cl2θ3-0.15 H2O 0.05 C2H5OH: C, 52.49;

H, 5.56; N, 10.74; Cl, 18.12. Found: C, 52.34; H, 5.47; N, 10.52; Cl, 17.99.

Example 37

(-fc)-(lR*. 2S*. 3S*. 5S*)-5-[5.6-Dichloro-2-(l-azetidinyl)-lH-benzimidazol-l-

vl]-3-rhvdroxvmethvl)- 1.2-cvclopentanediol

(±)(1R*, 2S*, 3S*, 5S*)-3-(Acetoxymethyl)-5-(2-bromo-5,6-dichloro-

1 H-benzimidazol- l-yl)-l,2-cyclopentanediyl diacetate (500 mg, 0.958 mmol)

was dissolved in ethanol (7 mL). Azetidine (Aldrich, 250 mg, 4.4 mmol as

98%) was added and the solution was refluxed under nitrogen for 48 hours.

Methanolic ammonia (saturated at 0° C, 20 mL) was added to the cooled

solution and this solution was stirred for an additional 18 hours. Volatiles were

evaporated, the residue was redissolved in ethanol (10 mL) and IN sodium

hydroxide (0.96 mL) was added. Volatiles were evaporated and the residual

solids were triturated with water (3 mL) and filtered. Resolidification of the

solid from acetonitrile-methanol gave title compound as white powder (146 mg,

41%), m.p. 221-222° C; ¹ H-NMR(DMSO-d6)δ 7.78 and 7.53 (both s, 1 each, 2

aromatic CH), 5.05 (t, J = 4.3 Hz, 1, OH), 4.91 (d, J = 5.3 Hz, 1, OH), 4.59 (d, J

= 3.7 Hz, 1, OH), 4.45-4.40 (m, 2, OCH and NCH), 4.25-4.15 (m, 4, 2 CH2N),

3.82-3.79 (m, 1, OCH), 3.66-3.43 (both m, 1 each, OCH2), 2.40-2.32 (m, 2,

CH2), 2.03-1.95 (m, 3, CH2 and NCH); mass spectrum (CI): 372(M+1). [See

Examples 8-10]

Anal. Calcd. for C16H19N3CI2O3: C, 51.63; H, 5.14; N, 11.29; Cl,

19.05. Found: C, 51.45; H, 5.10; N, 11.27; Cl, 18.96.

Example 38

(±WIR*. 2S*. 3R*. 5R*)-5-l5.6-Dichloro-2-(cvclopropylamino)-1H-

benzimidazol-1 -vl]-3-fhvdroxvmethvl)-l .2-cvclopentanediol

(±)(1R*, 2S*, 3R*, 5R*)-3-(Acetoxymethyl)-5-(2-bromo-5,6-dichloro-

1 H-benzimidazol- l-yl)-l,2-cyclopentanediyl diacetate (Example 39, 1.00 g, 1.87

mmol) , cyclopropylamine (Aldrich, 1.7 mL, 24 mmol) and absolute ethanol (10

mL) were refluxed under nitrogen for 48 hours. The reaction was cooled and 1

N sodium hydroxide (1.2 mL) was added. Volatiles were evaporated in vacuo

and the residual oily solid was chromatographed on silica gel. Elution with 5%

methanol - ethyl acetate gave fractions containing white powder (200 mg).

Recrystallization from 1 :1 water-ethanol gave (+/-)-(lR*, 2S*, 3R*, 5R*)-5-

[5,6-dichloro-2-(cyclopropylamino)-lH-benzimidazol-l-yl]- 3-(hydroxymethyl)-

1,2-cyclopentanediol as white crystals (180 mg, 40%); m.p. >250°C; ^! H-

NMR(DMSO-d6)δ 7.70 (m, 1, NH), 7.62 and 7.39 (both s, 1 each, 2

benzimidazole CH), 5.77 (br s, 1, OH), 5.13 (d, J = 5.3 Hz, 1, OH), 4.95 - 4.80

(m, 1, CHN), 4.48 (t, J = 4.7 Hz, 1, CH2OH), 4.2 - 4.0 (m, 2, 2 OCH), 3.7 - 4.0

(m, 2, OCH2), 2.9 - 2.65 (m, 1, OCH), 2.2 - 1.8 (m, 3, CH2 and CH); mass

spectrum (CI): 372(M+1). [See Examples 10-14]

Anal. Calcd. for Ci6Hι9N3Cl2θ3: C, 51.63; H, 5.14; N, 11.29; Cl, 19.05.

Found: C, 51.53; H, 5.18; N, 11.22; Cl, 18.97.

Example 39

(±WIR*. 2S*. 3R*. 5S*)-5-[5.6-Dichloro-2-(cvclopropylamino)-

1 H-benzimidazol-1 -vn-3-methvl-1.2-cvclopentanediol

Part A. (±WIS*. 2R*. 3R*. 5R*)-5-(5.6-Dich1oro-1H-henzimidazol-l-

vl)-3-(hvdroxvmethvl)-1.2-cvclopentanediol

(±)-(lR*, 2S*, 3S*,

5 S * )-3 -( Acetoxymethy 1 )-5 -(5 ,6-dichloro- 1 H-benzimidazol

-l-yl)-l,2-cyclopentanediyl diacetate (Example 2, 3.00 g, 6.77 mmol) was

dissolved in methanol (100 mL). Methanol saturated with ammonia at 0°C (100

mL) was added and the solution stirred at ambient temperature overnight.

Volatiles were evaporated in vacuo and the residual solid slurried with water and

filtered to give title compound as tan powder (2.02 g, 94%).

Part B. (±WIR*. 2S*. 3R*.

5S*)-5-(5.6-Dichloro-lH-ben7.imidazol-l-vl)-3-iodo-1.2-cv clopentanediol

(±)-(lS*, 2R*, 3R*, 5R*)-5-(5,6-Dichloro-l H-benzimidazol-1 -yl)-3-

(hydroxymethyl)-l,2-cyclopentanediol (Part A, 2.00 g, 6.31 mmol) was

dissolved in dry DMF (15 mL) under nitrogen and cooled (ice bath) while a

solution of methyltriphenoxyphosphonium iodide (Aldrich, 3.27 g, 6.94 mmol)

in dry DMF (15 mL) was added dropwise over 20 minutes. Stirring was

continued in the ice bath for an additional 30 minutes and then at ambient

temperature for 18 hours. Volatiles were evaporated in vacuo and the residue

chromatographed on silica gel. Product was eluted with 2% methanol-

chloroform to give, after evaporation of solvents, a pale yellow powder (750

mg, 28%); ¹ H-NMR(DMSO-d6δ 8.51 , 8.08, and 7.97 (all s, 1 each, 3

benzimidazole CH), 5.20 (d, J = 6.7 Hz, 1, OH), 5.04 (d, J = 4.9 Hz, 1, OH), 4.8-

4.6 (m, 1, NCH), 4.3-4.2 (m, 1, OCH), 3.8-3.7 (m, 1, OCH), 3.6-3.4 (m, 2,

CH2I), 2.55-2.40 (m, CH overlapping solvent), 2.35-2.20 (m, 1, CH), 1.75-1.50

(m, l, CH).

Part C. (±W1R*. 2S*. 3R*.

5S*)-5-(5.6-Dichloro-lH-benzimidazol-l-vl)-3-methvl-1.2-c vclopentanedivl

diacetate

(±)-(lR*, 2S*, 3R*, 5S*)-5-(5,6-Dichloro-lH-benzimidazol-l-yl)-3-iodo

-1,2-cyclopentanediol (Part B, 0.73 g, 1.71 mmol) in ethanol (200 mL) was

shaken with 5% Pd on carbon (140 mg) with triethylamine (0.24 mL) under

hydrogen (50 psi) on a Parr shaker for 7.5 hours. The catalyst was filtered off

(Celite) and the ethanol filtrate evaporated to a white solid. To this solid was

added pyridine (15 mL) and acetic anhydride (1.3 mL). The resulting solution

was stirred at ambient temperature for 18 hours. The volatiles were evaporated

and the residual oil was dissolved in chloroform (50 mL). The chloroform

solution was extracted with aqueous sodium bicarbonate and dried (sodium

sulfate). Evaporation of the chloroform left title compound as a yellow glass

(560 mg, 85%); ¹ H-NMR(DMSO-d6)δ: 8.61, 8.15, and 7.97 (all s, 1 each, 3

benzimidazole CH), 5.60-5.45 (m, 1, OCH), 5.20-4.95 (m, 2, OCH and NCH),

2.50-2.15 (m, 3, CH2 and CH), 2.09 and 1.95 (both s, 3 each, 2 OAc), 1.20 (d, J

= 6.5 Hz, 3, CHCH3).

Part D. (±WIR*. 2S*. 3R*. 5S*)-5-(2-Bromo-

5.6-dichloro- 1 H-benzimidazol- 1 -vl)-3-methvl-1.2-cvclopentanedivl diacetate

(±)-(lR*, 2S*, 3R*, 5S*)-5-(5,6-Dichloro-l H-benzimidazol- l-yl)-3-

methyl

-1,2-cyclopentanediyl diacetate (Part C, 550 mg, 1.43 mmol) was dissolved in

dry tetrahydrofuran (15 mL). N-bromosuccinimide (520 mg, 2.92 mmol) was

added and the resulting solution refluxed vigorously for 10 minutes. An

additional portion of N-bromosuccinimide (100 mg) was added and reflux

continued an additional 5 minutes. At this point, TLC (silical gel plates

developed with 5% methanol-chloroform) showed starting material has been

converted to a slightly higher Rf UV-absorbing spot. The reaction mixture was

quenched by cooling (ice bath) and diluted with chloroform (50 mL). This

solution was washed with water and dried (sodium sulfate). Evaporation left a

yellow solid which was chromatographed on silica gel. Title compound was

eluted with 5% methanol-chloroform and triturated in ethyl acetate to give white

powder (460 mg, 68%), m.p. 235-236°C dec; ¹ H-NMR(DMSO-d6)δ: 8.38

and 7.97 (both s, 1 each, 2 benzimidazole CH), 5.75-5.65 (m, 1, OCH), 5.2-5.0

(m, 2, OCH and NCH), 2.1 1 (s) overlapped by 2.2-2.05 (m, total 6, OAc with

CH2 and CH), 1.95 (s, 3, OAc), 1.22 (d, J = 6.3 Hz, 3, CHCH3); mass spectrum

(CI): 463 (M+l).

Part E. (±WIR*. 2S*. 3R*. 5S*)-5-[5.6-Dichloro-2-(cvclopropylamino)-

1 H-benzimidazol- 1 -yl]-3-methyl- 1.2-cvclopentanediol

(±)-(lR*, 2S*, 3R*, 5S*)-5-(2-Bromo-

5 ,6-dichloro- 1 H-benzimidazol- 1 -y 1)

-3-methyl-l,2-cyclopentanediyl diacetate (Part D, 350 mg, 0.75 mmole) and

cyclopropylamine (Aldrich, 0.53 mL) were refluxed in methoxyethanol (5 mL)

for 5 hours. 1 N sodium hydroxide (0.75 mL) was added to the cooled reaction

mixture and volatiles were evaporated in vacuo. The residue was

chromatographed on silica gel. Product was eluted with 5% methanol-

chloroform. Recrystallization from methanol-ethyl acetate gave (±)-(lR*, 2S*, 3R*, 5S*)-5-[5,6-dichloro-2-(cyclopropylamino)-lH-benzimidazol-l- yl]-3-

methyl- 1,2-cyclopentanediol as white crystals (170 mg, 64%); m.p. 231-233°C;

¹ H-NMR(DMSO-d6)δ: 7.48 and 7.39 (both s, 1 each, 2 benzimidazole CH),

7.10 (m, 1, NH), 4.83 (d, J = 5.9 Hz, 1, OH), 4.74 (d, J = 5.1 Hz, 1, OH), 4.5-4.3

(m, 2, NCH and OCH), 3.7-3.6 (m, 1, OCH), 2.85-2.7 (m, 1, CHNH), 2.1-1.8

(m, 2, CH2 and CH), 1.7-1.5 (m, 1, CH), 1.16 (d, J = 5.4 Hz, 3, CHCHj), 0.8-

0.5 (m, 4, 2 CH2 of cyclopropyl); mass spectrum (CI): 356 (M+l). [See

Examples 1 and 2]

Anal- Calcd. for Ci6Hι9N3Cl2θ2: C, 53.95; H, 5.38; N, 1 1.80; Cl,

19.90. Found: C, 53.75; H, 5.45; N, 11.71 ; Cl, 19.98.

Example 40

(IR. 2S. 3S. 5S)-5-[2-(/gr/-Butvlamino)-5.6-dichloro-lH-benzimidazol-l-vn -3-

(hvdroxv ethvl)- 1.2-cvclopentanediol

A solution of (IR, 2S, 3S, 5S)-5-(2-bromo-5,6-dichloro-lH-

benzimidazol-l-yl)-3-(hydroxymethyl)- 1,2-cyclopentanediol (500 mg, 1.26

mmole) was stirred in terf-butylamine (Aldrich, 98%, 20 mL) in a Parr bomb

maintained at 148° C (oil bath) for 48 hours. The bomb was cooled and the

resulting pale yellow solution diluted with ethanol containing 1 N sodium

hydroxide (1.2 mL). Volatiles were evaporated in vacuo and the residue was

chromatographed on silica gel. Title compound was eluted with 10% methanol-

chloroform as a colorless oil. The oil was dissolved in absolute ethanol,

concentrated to an oil, and triturated with water (3 mL) to give (IR, 2S, 3S, 5S)-

5-[2-( /7-butylamino)-5,6-dichloro- 1 H-benzimidazol- 1 -yl]-3-(hydroxymethyl)-

1 ,2-cyclopentanediol as white powder (303 mg, 61 %), m.p.: collapses to glass

at 1 16-150°C; ¹ H-NMR(DMSO-d6)δ: 7.63 and 7.43 (both s, 2, aromatic CH),

6.15 (s, 1, NH), 5.08 (t, J = 4.3 Hz, 1, OH), 4.85 (d, J = 7.4 Hz, 1, OH), 4.71 (d,

J = 3.8 Hz, 1, OH), 4.7-4.5 (m, 1, NCH), 4.45-4.3 (m, 1, OCH), 3.80 (m, 1,

OCH), 3.7-3.4 (m, 2, OCH2), 2.2-1.85 (m, 3, CH2 and CH of cyclopentane),

1.47 (s, 9, 3 CH3); mass spectrum (CI): 388(M+1); [α] ²⁰ 589 -4.0°, [α] ²⁰ 578 -

4.3°, [α] ²⁰ 546 -6.0°, [α] ²⁰ 436 -22.6°, [α] ²⁰ 365 -82.1 ° (c = 0.420, methanol).

[See Examples 25-28, 30 and 31]

Anal. Calcd. for C17H23N3C.2O3-O.4O H2O: C, 51.63; H, 6.07; N,

10.62; Cl, 17.93. Found: C, 51.50; H, 5.99; N, 10.54; Cl, 17.96.

Example 41

(±WIR*. 2S*. 3S*. 5S*)-5-[2-(fgr/-Butvlamino)-5.6-dichloro-lH-benzimidazol-

1 -vll-3-(hvdroxvmethvl)- 1.2-cvclopentanediol

A solution of (±)-(lR*, 2S*, 3S*, 5S*)-5-(2-bromo-5,6-dichloro-lH-

benzimidazol-l-yl)-3-(hydroxymethyl)- 1,2-cyclopentanediol (750 mg, 1.44

mmole) was stirred in ter/-butylamine (Aldrich, 98%, 25 mL) in a Parr bomb

maintained at 90°C (oil bath) for 6 days. Volatiles were evaporated in vacuo

and the residual solids refluxed in ethanol (30 mL) with aqueous dimethylamine

(Aldrich, 40%, 2 mL) for one hour. Volatiles were evaporated and the residual

solids chromatographed on silica gel. Elution with 10% methanol-ethyl acetate

gave title compound as colorless glass. Solidification from water gave (±)-(lR*,

2S*, 3S*, 5S*)-5-[2-(/er/-butylamino)-5,6-dichloro-l H-benzimidazol-1 -yl]-3- (hydroxymethyl)- 1,2-cyclopentanediol as a white powder (150 mg, 26%); m.p.

130- 132 °C; ^l H-NMR(DMSO-d6) identical with that of the enatiomer described in Example 30. [See Examples 1-4]

Anal- Calcd. for C17H23N3CI2O3 O.65 H2O 0.07 C2H5OH: C, 51.18:

H, 5.94; N, 10.47; Cl, 17.63. Found: C, 51.34; H, 6.06; N, 10.37; Cl, 17.58.

Example 42

(±)-(lR*. 2S*. 3S*. 5S*)-5-[5.6-Dichloro-2-(isopropvlamino)-lH-benzimidazol-

1 -vn-3-(hvdroxvmethvl)- 1.2-cvclopentanediol

(±)-(lR*, 2S*, 3S*, 5S*)-3-(Acetoxymethyl)-5-(2-bromo-5,6-dichloro-lH-

benzimidazol-l-yl)-l,2-cyclopentanediyI diacetate (750 mg, 1.44 mmole) was

refluxed in ethanol (10 mL) with isopropylamine (1.22 mL, Aldrich) under

nitrogen for 18 hours. A second portion of isopropylamine (1.22 mL) was added

and reflux continued for an additional 24 hours. Volatiles were evaporated, the

residue was redissolved in ethanol, 1 N sodium hydroxide (1.44 mL) was added,

and volatiles were reevaporated. The residue was chromatographed on a silica

gel column. Title compound was eluted with 10% methanol-chloroform as a

colorless glass. The glass was crystallized from ethyl acetate - hexanes to give

(±)-(lR*, 2S*, 3S*, 5S*)-5-[5,6-dichloro-2-(isopropylamino)-lH-benzimidazol-

l-yl]-3-(hydroxymethyl)- 1,2-cyclopentanediol as white crystals (305 mg, 57%);

m.p. 213-214°C; ¹ H-NMR(DMSO-dό) identical with that of the enantiomer

described in Example 23 .[See Examples 1-4]

Anal. Calcd. for C16H2IN3CI2O3: C, 51.35; H, 5.66; N, 11.23; Cl,

18.95. Found: C, 51.27; H, 5.69; N, 11.17; Cl, 18.88.