The present invention refers to nitric oxide donor aspirin derivatives, a process for their preparation and pharmaceutical compositions containing them.

Aspirin (acetylsalicylic acid) is a well established drug belonging to the class of non steroidal anti-inflammatory drugs (NSAIDs) which displays a variety of actions including anti-inflammatory, analgesic, antipyretic and antithrombotic activities. The major drawback which limits its use is a relevant gastrotoxicity that is responsible for gastric ulceration, exacerbation of peptic ulcer symptoms, gastrointestinal hemorrage and erosive gastritis (Goodman & Gilman' s The Pharmacological Basis of Therapeutics; 10 ^th ed.; McGraw-Hill, Chapter 27) .

Many attempts were made to obviate these side effects. A recent strategy to decrease the gastrotoxicity of aspirin was the combination of aspirin with nitric oxide-donor moieties.

Aspirin with nitric oxide-donor moieties (NO-releasing aspririn derivatives) are known in the art and are reported to have improved gastrointestinal and cardiovascular safety profile over aspirin. WO 92/01668 discloses mononitrate aspirin derivatives in which the nitrooxy group is linked to the carboxylic group through an ester or amidic bond. These NO-releasing apririn derivatives showed vasorelaxant and antianginal effects.

WO 95/30641 and WO 97/16405 disclose NO releasing derivatives of aspirin in which the nitric oxide-donor moiety has been joined through an ester linkage to the carboxylic group of the aspirin. These compounds have antiinflammatory, analgesic and anti-thrombotic activity with lower gastrointestinal toxicity in comparison with aspirin. US 5,859,053 discloses dinitrates ester of aspirin in which NO-donor moiety has been joined through an ester or an amide linkage to the carboxylic group of the aspirin, and their use for the alleviation of pain, inhibition of platelet aggregation, lowering of fever and for prevention of cardiovascular disorders.

A limit of the NO releasing aspirins of the prior art is the high enzymatic liability of the o-acetyloxy group consequently these substances are rapidly metabolised to salicylic acid in human serum without any formation of relevant amount of aspirin.

Additional disadvantages of many NO releasing aspirin derivatives are due to high hydrophobicity and poor water solubility of the compounds. Because of these disadvantages their systemic absorption is low.

There is a need, therefore, for drugs which retain the therapeutic effects of aspirin and have decreased undesidered side effects.

It is an object of the present invention to provide aspirin nitroderivatives of general formula (I) and pharmaceutically acceptable salts or stereoisomers thereof

(D wherein z is H or a straight or branched C ₁ -C ₄ alkyl, preferably z is H or CH3, more preferably z is H; the groups Xi-R and X-R ¹ can be independently linked to the aryl group in position 3, 4 or 5; Xi is selected from -O-, -O-CO-, -OCOO-, -S-, -S(O)-, - S(O) ₂ -, -CH ₂ -, preferably Xi is 0;

R is selected from the group consisting of

A) (R ⁰ K-CH(ONO ₂ ) -R ² B) (R ⁰ ) _t -CH (ONO ₂ ) - (CR ³ R ⁴ ) _P -CH(ONO ₂ ) -R ²

C) (R ⁰ ) _t -0- (CR ³ R ⁴ ) _n -CH (ONO ₂ ) -R ²

D) (R ⁰ ) _t -0- (CR ³ R ⁴ ) _n -CH (ONO ₂ ) - (CR ³ R ⁴ ) _p -CH (ONO ₂ ) -R ² wherein

R ⁰ is a straight or branched Ci-Cio alkylene, preferably R ⁰ is Ci-Cε alkylene; more preferably R ⁰ is C1-C3 alkylene; t is an integer selected from O to 1, preferably t is 1;

R ² is -H or straight or branched C ₁ -C ₄ alkyl, preferably R ² is -H or C ₁ alkyl; n is an integer from 0 to 6; p is an integer from 0 to 6, preferably p is 0;

3 4 R and R are independently selected from hydrogen or straight or branched C ₁ -C ₄ alkyl;

X is selected from -0-, -0-C0-, -OCOO-, and -CH ₂ -; R ¹ is selected from the group consisting of a) (R ⁵ U-CH (NH ₂ ) -R ⁶ b) (R ⁵ U-CH (NH ₂ ) - (CR ⁷ R ⁸ ) _q -CH (OH) -R ⁶ c) (R ⁵ U-CH (COOH) -R ⁶

d) (R ⁵ ) _m - N Y

wherein Y i s -0- or -N- ;

R ⁵ i s a straight or branched C ₁ -C ₁ 0 al kylene , preferably R ⁵ i s Ci-Cε al kylene ; more preferably R ⁵ i s Ci al kylene ; m i s the integer 0 or 1 ; q is an integer from 0 to 6, preferably q is 0; R ⁶ i s -H or straight or branched C ₁ -C ₄ al kyl , preferably

R ⁶ i s -H or C ₁ al kyl ; 7 8

R and R are independently selected from hydrogen or straight or branched C ₁ -C ₄ alkyl; with the proviso that t is 0 or 1 when Xi is -CH ₂ - and t is 1 when X ₁ is selected from -0-, -0-C0-, -OCOO-, -S-, - S(O)-, -S(O) ₂ -.

The compounds of the invention, when administered to a subject, provide a good bioavailability of aspirin, they have less side effects over aspirin and a better water solubility than the known NO releasing aspirin derivatives.

The term "C1-C4 alkyl" as used herein refers to branched or straight alkyl groups comprising 1 to 4 carbon atoms, including methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl and the like. The term "C1-C10 alkylene" as used herein refers to branched or straight C1-C10 hydrocarbon chain such as methylene, ethylene, propylene, isopropylene, n-butylene, pentylene, n-hexylene and the like.

As stated above, the invention includes also the pharmaceutically acceptable salts of the compounds of formula (I) and stereoisomers thereof.

Examples of pharmaceutically acceptable salts are either those with inorganic bases, such as sodium, potassium, calcium and aluminium hydroxides, or with organic bases, such as lysine, arginine, triethylamine, dibenzylamine, piperidine and other pharmaceutical acceptable organic amines or bases as those reported for example in Wermuth, CG. and Stahl, P.H.Pharmaceutical Salts: Properties, Selection, and Use - A Handbook Verlag Helvetica Chimica Acta, 2002.

The compounds according to the present invention, when they contain in the molecule one salifiable nitrogen atom, can be transformed into the corresponding salts by reaction, in an organic solvent such as acetonitrile, tetrahydrofuran, with the corresponding organic or inorganic acids.

Examples of organic acids are oxalic, tartaric, maleic, succinic, citric and trifluoroacetic acids. Examples of inorganic acids are nitric, hydrochloric, sulphuric, phosphoric acids and other pharmaceutical acceptable acid as those reported for example in Wermuth, CG. and Stahl, P.H.Pharmaceutical Salts: Properties, Selection, and Use - A Handbook Verlag Helvetica Chimica Acta, 2002.

The compounds of the invention that have one or more asymmetric carbon atoms can exist as optically pure enantiomers, pure diastereomers, enantiomers mixtures, diastereomers mixtures, enantiomer racemic mixtures, racemates or racemate mixtures. Within the scope of the invention are also all the possible isomers, stereoisomers and their mixtures of the compounds of formula (I), including mixtures enriched in a particular isomer.

Particularly preferred compounds of formula (I) are:

( i :

HCl

( 2 : o:

HCI

(4:

HCl

(5:

(6:

10

( 7 :

( 8 )

o:

The compounds of the invention can be used for preventing and treating thrombotic cardiovascular events caused by platelet aggregation, thrombosis, and subsequent ischemic clinical events, including thrombotic or thromboembolic stroke, myocardial ischemia, myocardial infarction, angina pectoris, transient ischemic attack, reversible ischemic neurologic deficits, and any similar thrombotic event in any vascular bed (splanchnic, renal, aortic, peripheral, etc.) .

The compounds of the invention are useful for the relief of pain, fever and inflammation of a variety of conditions including rheumatic fever, symptoms associated with influenza or other viral infections, common cold, low back and neck pain, dysmenorrhea, headhache, toothache, sprains and strains, myositis, neuralgia, synovitis, arthritis, including rheumatoid arthritis degenerative joint diseases (osteoarthritis) , gout and ankylosing spondylitis, bursitis, burns, injuries, following surgical and dental procedures.

The compounds of formula (I) above reported can be used to treat cancers for example tumors, malignancies, neoplasms, and other dysproliferative diseases, which can be treated according to the invention, including leukemias such as myeloid and lymphocytic leukemias, lymphomas, myeloproliferative diseases, and solid tumors, such as but not limited to sarcomas and carcinomas such as fibrosarcoma, chondrosarcoma, osteogenic sarcoma, angiosarcoma, endotheliosarcoma, lymphangiosarcoma, lymphangioendothelio- sarcoma, synovioma, mesothelioma, colon carcinoma, gastric cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, carcinoma of the tongue, papillary adenocarcinomas, cystadenocarcinoma, medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatoma, bile duct carcinoma, choriocarcinoma, cervical cancer, testicular tumor, lung carcinoma, small and not small cell lung carcinoma, bladder carcinoma, epithelial carcinoma, glioma, astrocytoma, medulloblastoma, craniopharyngioma, hemangioblastoma, oligodendroglioma, melanoma, neuroblastoma, and retinoblastoma.

In particular the compound of formula (I) above reported can be used to treat cancers such as colon carcinoma, gastric cancer, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, adenocarcinoma, medullary carcinoma, renal cell carcinoma, bladder carcinoma.

The compounds of formula (I) can be used in combination with either cell therapy, radiotherapy or any kind of chemotherapy such as alkylating agents (nitrogen mustards, cisplatin, etc) , antimetabolites (methotrexate, 5- fluorouracil, etc) , natural products (vincristine, doxorubicin, topotecan, etoposide, etc) , hormones and antagonists (tamoxifen, prednisone, flutamide, leuprolide, etc), biological response modifiers (IFN-alfa, IL-2, Antibodies, etc) , and any other modifier of specific signaling pathway (HDAC inhibitors, Carbon Anhydrase inhibitors, etc) . The present invention also provides pharmaceutical kits comprising a compound of formula (I) and at least a chemotherapeutic agent.

The present invention also provides pharmaceutical kits comprising one or more containers filled with one or more of the compounds and/or compositions of the present invention and one or more chemotherapeutic agents reported above as combined preparation for simultaneous, separated or sequential use.

The compounds of the invention can be used alone or in combination with NSAIDs, such as those described in Goodman and Gilman's, The Pharmacological Basis of Therapeutics, Tenth Edition, p. 687-716.

Another object of the present invention refers to pharmaceutical compositions containing at least a compound of formula (I) together with non-toxic adiuvants and/or carriers usually employed in the pharmaceutical field.

The daily dose of active ingredient that should be administered can be a single dose or it can be an effective amount divided into several smaller doses that are to be administered throughout the day. Usually, total daily dose may be in amounts preferably from 50 to 1000 mg. The dosage regimen and administration frequency for treating the mentioned diseases with the compound of the invention and/or with the pharmaceutical compositions of the present invention will be selected in accordance with a variety of factors, including for example age, body weight, sex and medical condition of the patient as well as severity of the disease, route of administration, pharmacological considerations and eventual concomitant therapy with other drugs. In some instances, dosage levels below or above the aforesaid range and/or more frequent may be adequate, and this logically will be within the judgment of the physician and will depend on the disease state.

The compounds of the invention may be administered orally, parenterally, rectally or topically, by inhalation or aerosol, in formulations eventually containing conventional non-toxic pharmaceutically acceptable carriers, adjuvants and vehicles as desired. Topical administration may also involve the use of transdermal administration such as transdermal patches or iontophoresis devices. The term "parenteral" as used herein, includes subcutaneous, intravenous, intramuscular, intrasternal injection or infusion techniques.

Injectable preparations, for example sterile injectable aqueous or oleaginous suspensions may be formulated according to known art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally acceptable diluent or solvent. Among the acceptable vehicles and solvents are water, Ringer's solution and isotonic sodium chloride. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono or diglycerides, in addition fatty acids such as oleic acid find use in the preparation of injectables. Suppositories for rectal administration of the drug can be prepared by mixing the active ingredient with a suitable non-irritating excipient, such as cocoa butter and polyethylene glycols. Solid dosage forms for oral administration may include capsules, tablets, pills, powders, granules and gels. In such solid dosage forms, the active compound may be admixed with at least one inert diluent such as sucrose, lactose or starch. Such dosage forms may also comprise, as in normal practice, additional substances other than inert diluents, e.g. lubricating agents such as magnesium stearate. In the case of capsules, tablets and pills, the dosage forms may also comprise buffering agents. Tablets and pills can additionally be prepared with enteric coatings. Liquid dosage forms for oral administration may include pharmaceutically acceptable emulsions, solutions, suspensions, syrups and elixirs containing inert diluents commonly used in the art, such as water. Such compositions may also comprise adjuvants, such as wetting agents, emulsifying and suspending agents, and sweetening, flavouring and the like.

Synthetic procedure

1) The compounds of general formula (I), wherein X, Xi, R and R ¹ are as above defined and wherein z is H can be obtained:

1-1) by reacting aspirin with ClCH ₂ Br in an organic solvent such as halogenated hydrocarbons, aromatic hydrocarbons, ethers, dipolar aprotic solvents, in particular tetrahydrofuran or N, N-dimethylformamide and mixtures thereof, in the presence of a suitable base such as a tertiary amine or K ⁺ t-BuO ^~ to give the chloromethyl ester at a temperature between -40 ⁰ C and reflux temperature for a time between a few minutes and 72 hours, and

1-2) by reacting the chloromethyl 2- (acetyloxy) benzoate obtained in the step 1-1) with a carboxylic acid of formula

(H)

(II) wherein Xi is as above defined, R ⁹ is selected from the group consisting of A ₁ ) (R ⁰ K-CH(Q ¹ ) -R ²

B ₁ ) (R ⁰ ) _t -CH (Q ¹ ) - (CR ³ R ⁴ ) _p -CH (Q ¹ ) -R ² C ₁ ) (R ⁰ ) _t -0- (CRV) _n -CH(Q ¹ ) -R ²

D ₁ ) (R ⁰ ) _t -0- (CR ³ R ⁴ ) _n -CH (Q ¹ ) - (CR ³ R ⁴ ) _p -CH (Q ¹ ) -R ² wherein R ⁰ , R ² , R ³ , R ⁴ , t, n and p are as above defined and Q ¹ is ONO ₂ or Q ² , wherein Q ² is a chlorine atom, a bromine atom, a iodine atom, a mesyl group, a tosyl group, and

Z is OH or -X-R ¹⁰ , wherein R ¹⁰ is selected from the group consisting of bi) (R ⁵ U-CH (NHP) - (CR ⁷ R ⁸ ) _q -CH (OP ¹ ) -R ⁶ C ₁ ) (R ⁵ U-CH(COOP ² ) -R ⁶

Cl ₁ ) (R ⁵ ) _m " N Y

wherein X, R ⁵ , R ⁶ , R ⁷ , R ⁸ and q are as above defined and P is a amino protecting group such as Boc, Fmoc or those described in T. W. Greene "Protective groups in organic synthesis", Harvard University Press, 1980,

P ¹ is a hydroxyl protecting group such as tetrahydropyranyl ether (THP) and those described in T. W. Greene "Protective groups in organic synthesis", Harvard University Press, 1980 2 ^nd edition,

P ² is a carboxylic protecting group such as tert-butyl ester and those described in T. W. Greene "Protective groups in organic synthesis", Harvard University Press, 1980; the reaction may be carried out in a suitable organic solvent such as halogenated hydrocarbons, ethers, aromatic hydrocarbons, dipolar aprotic solvents, preferably DMF, in the presence of a suitable base such as tertiary amines, in particular triethylamine, or cesium carbonate, and

1-3) when Q ¹ is Q ² , by converting the compound obtained in step 1-2) into nitro derivative by reaction with a nitrate source such as silver nitrate, lithium nitrate, sodium nitrate, potassium nitrate, magnesium nitrate, calcium nitrate, iron nitrate, zinc nitrate or tetraalkylammonium nitrate (wherein alkyl is Ci-Cio alkyl) in a suitable organic solvent such as acetonitrile, tetrahydrofurane, methyl ethyl ketone, ethyl acetate, DMF, the reaction is carried out, in the dark, at a temperature from room temperature to the boiling temperature of the solvent. Preferred nitrate source is silver nitrate; and

1-4) when Z is -OH by reacting the compound obtained in the step 1-2) or 1-3) with a compound of formula (III)

W-R ¹⁰ (III) wherein W is a chlorine atom, a bromine atom, a iodine atom, -COOH, -COCl, -0-COCl or -CO-O-R _a , wherein R _a is selected from the group consisting of: pentafluorophenyl, 4- nitrophenyl, - (N-succimidyl) , and R ¹⁰ is selected from the group consisting of ai) , bi) , Ci) , di) ,

- 1-4-a) the reaction of a compound of formula (III) wherein W = -COOH, with a compound obtained in step 1-2) or 1-3) may be carried out in presence of a condensing agent as dicyclohexylcarbodiimide (DCC), N'-(3- dimethylaminopropyl) -N-ethylcarbodiimide hydrochloride

(EDAC) N, N' -carbonyldiimidazole (CDI), in the presence or not of a base as for example as N, N-dimethylamino pyridine (DMAP) . The reaction is carried out in an inert dry organic solvent such as N, N' -dimethylformamide, tetrahydrofuran, benzene, toluene, dioxane, a polyhalogenated aliphatic hydrocarbon at a temperature from -20 ⁰ C and 50 ⁰ C. The reaction is completed within a time range from 30 minutes to 36 hours;

1-4-b) the reaction of a compound of formula (III) wherein W = -CO-O-R _a , with a compound obtained in step 1- 2) or 1-3) may be carried out in presence of a catalyst, such as N, N-dimethylamino pyridine (DMAP) or in the presence of DMAP and a Lewis acid such as Sc (OTf) 3 or Bi(OTf) ₃ . The reaction is carried out in an inert organic solvent such as N, N' -dimethylformamide, tetrahydrofuran, benzene, toluene, dioxane, a polyhalogenated aliphatic hydrocarbon at a temperature from -20 ⁰ C and 40 ⁰ C. The reaction is completed within a time range from 30 minutes to 36 hours;

1-4-c) the reaction of a compound of formula (III) wherein W = -COCl, -O-COCl with a compound obtained in the step 1-2) or 1-3) may be carried out in presence of of an organic base such as N, N-dimethylamino pyridine (DMAP), triethylamine, pyridine. The reaction is carried out in an inert organic solvent such as N, N'- dimethylformamide, tetrahydrofuran, benzene, toluene, dioxane, a polyhalogenated aliphatic hydrocarbon at a temperature from -20 ⁰ C and 40 ⁰ C. The reaction is completed within a time range from 30 minutes to 36 hours; 1-4-d) the reaction of a compound of formula (III) wherein W is a chlorine atom, a bromine atom, a iodine atom, with a compound obtained in the step 1-2) or 1-3) may be carried out in presence of an organic or inorganic base such as K2CO3, NaH, DBU, in an aprotic polar solvent such as THF, DMF, CH ₃ CN at temperatures ranging between - 20 ⁰ C to 100 ⁰ C; and

1-5) optionally deprotecting the compound obtained in step 1-2), 1-3) or 1-4) as described in T. W. Greene

"Protective groups in organic synthesis", Harvard University

Press, 1980, 2 ^nd edition. Fluoride ion is the preferred method for removing silyl ether protecting group.

Trifluoroacetic acid or anhydrous inorganic acid are the preferred method for removing Boc protecting group, anhydrous organic or inorganic acid is the preferred method for removing THP protecting group. Organic base such as piperidine is the preferred method for removing Fmoc protecting group. Aqueous or anhydrous organic or inorganic acid is the preferred method for removing t-butyl ester protecting group.

2) The compounds of general formula (I), wherein X, R and

R ¹ are as above defined and wherein z is CH ₃ can be obtained: 2-1) by reacting the acylchloride of aspirin with acetaldehyde in the presence of zinc chloride (WO 04/018484) :

2-2) by reacting the 1-chloroethyl 2- (acetyloxy) benzoate obtained in the step 2-1) with a carboxylic acid of formula (II) defined above. The reaction is carried out according to the method described in 1-2) . 2-3) when Q ¹ is Q ² , by converting the compound obtained in step 2-2) according to the method described in 1-3); and

2-4) when Z is -OH by reacting the compound obtained in the step 2-2) or 2-3) with a compound of formula (III) as defined above, according to the method described in 1-4); and

2-5) optionally deprotecting the compound obtained in step 2-2), 2-3) or 2-4) according to the method described in 1-5) .

3) Compounds (II) wherein R is as above defined, Xi is 0 or S, Z is X-R ¹⁰ , and R ¹⁰ is selected from the group consisting of ai) , bi) , or Ci) can be obtained: 3-1) by reacting the aldehyde of formula (IV)

OH (IV) with the halogen derivatives of formula (V)

HaI-R ¹¹

(V) wherein R ¹¹ is selected from the group consisting of : Ai) , Bi) , Ci) , Di) wherein p is an integer from 1 to 6 B ₂ ) R°-CH=CH-R ² D ₂ ) R°-0- (CR ³ R ⁴ ) _n -CH=CH-R ² according to method described in 1-4-d) , and 3-2) when Q ¹ is Q ² , by converting the compound obtained in the step 3-1) into nitro derivative as described in 1-3), and

3-3) when R ⁷ is selected from B ₂ ) or D ₂ ) by converting the product obtained in the step 3-1) by treatment with iodine and silver nitrate in acetonitrile at a temperature between -20 ⁰ C and 80 ⁰ C, and

3-4) by reacting the compound obtained in the step 3-1) or 3-2) or 3-3) with a compound of formula (III) W-R ¹⁰

(III) wherein W and R ¹⁰ are as above defined, according to methods described in 1-4) , and

3-5) by reacting the compound obtained in the step 3-4) with a suitable oxidising agent such as potassium permanganate, sodium chlorite or sodium chlorite/H ₂ 0 ₂ in a suitable organic solvent such acetic acid and the like at a temperature from 0 to 80 ⁰ C for a time from 1 minute to 72 hours .

4) Compounds (II) wherein R ⁹ is as above defined, Xi is - 0-C(O)- or -0-C(O)-O , Z is X-R ¹⁰ , and R ¹⁰ is selected from the group consisting of ai) , bi) , or Ci) can be obtained: 4-1) by reacting the aldehyde of formula (IV)

(IV) with the compounds of formula (VI)

W-R ¹¹ (VI) wherein W is as above defined, R ¹¹ is selected from the group consisting of : Ai) , Bi) , Ci) , Di) , wherein p is an integer from 1 to 6 B ₂ ) R°-CH=CH-R ² D ₂ ) R°-0- (CR ³ R ⁴ ) _n -CH=CH-R ² according to method described in 1-4), and 4-2) when Q ¹ is Q ² , by converting the compound obtained in the step 4-1) into nitro derivative as described in 1-3), and

4-3) when R ¹¹ is selected from B ₂ ) or D ₂ ) by converting the product obtained in the step 4-1) in nitroderivatives as described in 3-3) , and

4-4) by reacting the compound obtained in the step 4-1) or 4-2) or 4-3) with a compound of formula (III)

W-R ¹⁰

(III) wherein W and R ¹⁰ are as above defined, according to methods described in 1-4), and

4-5) by reacting the compound obtained in the step 4-4) with a suitable oxidising agent as described in 3-5) .

5) Compounds (II) wherein R ⁹ is as above defined, Xi is - S(O)-, Z is X-R ¹⁰ , and R ¹⁰ is selected from the group consisting of ai) , bi) , or Ci) can be obtained

5-1) by reacting of compounds of formula (II) wherein Xi is -S- with a suitable oxidising agent such as mCPBA in a suitable organic solvent such methylene chloride and the like at a temperature from -80 ⁰ C to 0 ⁰ C for a time from 10 minute to 2 hours .

6) Compounds (II) wherein R ⁹ is as above defined, Xi is - S(O) ₂ -, Z is X-R ¹⁰ , and R ¹⁰ is selected from the group consisting of ai) , bi) , or Ci) can be obtained

6-1) by reacting of compounds of formula (II) wherein Xi is -S- with a suitable oxidising agent oxone, potassium permanganate, hydrogen peroxide in a suitable organic solvent such acetone, methanol and water and the like at a temperature from 0 ⁰ C to 40 ⁰ C for a time from 10 minute to 4 hours .

7) Compounds (II) wherein R ⁹ is as above defined, Xi is - CH ₂ -, Z is X-R ¹⁰ , and R ¹⁰ is selected from the group consisting of ai) , bi) , or Ci) are know in literature.

8) Compounds (II) wherein R ⁹ is selected from the group consisting of A ₁ ), B ₁ ), C ₁ ), D ₁ ), Z is X-R ¹⁰ , and R ¹⁰ is selected from the group consisting of di) and X is -CH ₂ - can be obtained

8-1) by reacting the ester of formula (VII)

(VII) wherein R' is methyl, ethyl, X ₁ is -O-, -S-, by reaction with the halogen derivatives of formula HaI-R ¹¹ (V) , wherein R ¹¹ is as above defined, as described in 1-4-d) , and 8-2) when Q ¹ is Q ² , by converting the compound obtained in the step 8-1) into nitro derivative as described in 1-3), and

8-3) when R ¹¹ is selected from B ₂ ) or D ₂ ) by converting the product obtained in the step 8-1) into nitro derivative as described in 3-3) , and

8-4) by hydrolysis of ester obtained in the steps 7-1), 7-2) or 7-3) according to methods well known in the literature . 8-5) when in the compounds (II) Xi is -S(O)- by oxidation of tiocompounds obtained in the step 8-4) as described in 5- 1) , and

8-6) when in the compounds (II) Xi is -S(O) ₂ - by oxidation of tiocompounds obtained in the step 8-4) as described in 6-1) .

The compounds (III), (IV), (V), (VI) and (VII) are commercially available or can be obtained by methods well known in the art.

Example 1

{ [2- (Acetyloxy) benzoyl] oxy}methyl 4- (morpholin-4-yl- methyl) -3- [3- (nitrooxy)propoxy]benzoate oxalate: compound (1)

Methyl 3- (3-bromopropoxy) -4- (morpholin-4-yl- methyl) benzoate

To a solution of methyl 3-hydroxy-4- (morpholin-4-yl- methyl) benzoate (1.00 g, 3.95 mmol) in CH ₃ CN (12 mL) K ₂ CO ₃

(0.66 g, 5.0 mmol) and 1, 3-dibromopropane (2 mL, 19.5 mmol) were added, then the mixture was heated at reflux for 6 hours. Thereafter the cooled reaction mixture was poured in

H ₂ O (50 mL) and extracted with EtOAc (3 x 50 mL) . The combined organic layers were washed with H ₂ O (25 mL) , brine

(25 mL) , dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 60/40 v/v) to give the title compound (0.30 g) as colourless oil. Yield: 20%. ¹ H-NMR (CDCl ₃ ) δ 2.33 (2H, qi) , 2.58 (4H, m) , 3.65 (4H, t) , 3.76 (4H, t) , 3.81 (3H, s) , 4.18 (2H, t) , 7.46 (IH, d,

Arom) , 7.55 (IH, s, Arom) , 7.66 (IH, d, Arom) . ¹³ C-NMR

(CDCl ₃ ) δ 29.9, 32.2, 52.2, 53.4, 56.2, 65.7, 66.6, 112.1,

122.1, 130.6, 132.1, 156.7, 166.8.

Methyl 4- (morpholin-4-yl-methyl) -3- [3- (nitrooxy) propoxy] benzoate

A solution of methyl 3- (3-bromopropoxy) -4- (morpholin-4-yl- methyl) benzoate (0.60 g, 1.60 mmol) and AgNO ₃ (0.55 g, 3.2 mmol) in CH ₃ CN (10 mL) was stirred at 70 ⁰ C for 3 h. Then brine was added to precipitate the excess of AgNO ₃ , the mixture was filtered through Celite and concentrated under reduced pressure. The residue was treated with CH2CI2 (50 mL) and H ₂ O (25 mL) . After separation the aqueous layer was extracted twice with CH ₂ Cl ₂ (50 mL) . The combined organic layers were dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 70/30 v/v) to give the title compound (0.28 g) as colourless oil. Yield: 50%.

¹ H-NMR (CD ₃ OD) δ 2.27 (2H, qi) , 2.50 (4H, t) , 3.60 (2H, s) , 3.68 (4H, t) , 3.89 (3H, s) , 4.17 (2H, t) , 4.74 (2H, t) , 7.47 (IH, d, Arom), 7.57 (2H, m, Arom) . ¹³ C-NMR (CD ₃ OD) δ 28.0, 52.7, 54.8, 57.5, 65.7, 67.8, 71.7, 113.0, 122.9, 132.1, 132.3, 158.4, 165.9. 4- (Morpholin-4-yl-methyl) -3- [3- (nitrooxy)propoxy] benzoic acid

A solution of methyl 4- (morpholin-4-yl-methyl) -3- [3-

(nitrooxy) propoxy] benzoate (0.20 g, 0.56 mmol) in MeOH (5 mL) and IN NaOH (2 mL) was stirred at room temperature for 4 h. Then the solvent was removed under reduced pressure, the residue was dissolved in H ₂ O (10 mL) , the pH adjusted to 7 and the product was extracted in continuous for 18 hours with EtOAc. The EtOAc layer was dried with MgSO ₄ , filtered and concentrated under reduced pressure to give the title compound (0.15 g) as colourless oil. Yield: 71%. 1H-NMR (DMSO-de) δ 2.18 (2H, qi) , 2.38 (4H, m) , 3.51 (2H, s) , 3.57 (4H, m) , 4.13 (2H, t) , 4.74 (2H, m) , 7.45 (2H, m, Arom) , 7.54 (IH, d, Arom) , 12.95 (IH, svvbr) .

{ [2- (Acetyloxy) benzoyl] oxy}methyl 4- (morpholin-4-yl- methyl) -3- [3- (nitrooxy) propoxy] benzoate oxalate

To solution of 4- (morpholin-4-yl-methyl) -3- [3- (nitrooxy) propoxy] benzoic acid (0.14 g, 0.41 mmol) in DMF (3 mL) were added CS2CO3 (0.07 g, 0.21 mmol) and after 10 min chloromethyl 2- (acetyloxy) benzoate (0.10 g, 0.41 mmol) . The mixture was stirred for 24 hours, then was poured in H2O (15 mL) and extracted with EtOAc (3 x 15 mL) . The combined organic layers were washed with H2O (20 mL) , brine (20 mL) , dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 70/30 v/v) to give the { [2- ( acetyloxy) benzoyl ] oxy } methyl 4- (morpholin-4-yl-methyl) -3- [3- (nitrooxy) propoxy] benzoate (0.17 g) as colourless oil. To a solution of { [2- (acetyloxy) benzoyl] oxy jmethyl 4- (morpholin-4-yl-methyl) -3- [3- (nitrooxy) propoxy] benzoate in EtOAc (2 mL) was added a solution of H ₂ C ₂ O ₄ (0.03 g, 1 eq) in EtOAc (2 mL) and the title compound (0.03 g) was obtained by filtration as white solid. Yield: 20%. 1H-NMR (DMSO-de) δ 2.20 (2H, t) , 2.26 (3H, s) , 2.68 (4H, m) , 3.65 (4H, IR) ₁ 3.81 (2H, s) , 4.18 (2H, t) , 4.74 (2H, t) ,

6.17 (2H, s) , 7.28 (IH, d, Arom) , 7.44 (IH, t, Arom) , 7.56

(2H, IR ₁ Arom), 7.64 (IH, d, Arom), 7.73 (IH, t, Arom), 7.98

(IH, d, Arom) . ¹³ C-NMR (DMSO-d ₆ ) δ 21.5, 27.0, 53.4, 55.7, 65.6, 66.0, 72.0, 81.3, 112.8, 122.7, 125.1, 127.4, 130.1, 130.4, 132.3, 136.0, 151.1, 157.7, 163.0, 163.6, 165.1, 170.0.

Example 2

{ [2- (Acetyloxy) benzoyl] oxy}methyl 3- (β-alanyloxy) -4- [3- (nitrooxy)propoxy]benzoate hydrochloride: compound (2) . 4- (3-Bromopropoxy) -3-hydroxybenzaldehyde

A solution of 3, 4-dihydroxy-benzaldehyde (1.20 g, 8.69 mmol) , 1, 3-dibromopropane (2.64 mL, 26.07 mmol) and KHCO3

(1.04 g, 10.43 mmol) in CH ₃ CN (20 mL) was refluxed for 4 hours. Then the mixture was poured in H2O (50 mL) and extracted twice with EtOAc (30 mL) ; the combined organic layers were washed with brine (10 mL) , dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 9/1 v/v) to give the title compound (1.05 g) as pale yellow oil. Yield: 47%.

¹ H-NMR (CDCl ₃ ) δ 2.42 (2H, qi) , 3.59 (2H, t) , 4.31 (2H, t) , 5.98 (IH, s) , 6.99 (IH, d, Arom) , 7.41-7.46 (2H, m, Arom) , 9.84 (IH, s) . ¹³ C-NMR (CDCl ₃ ) δ 29.3, 31.8, 66.9, 111.2, 114.4, 124.6, 130.8, 146.2, 150.9, 162.9, 191.1. MS

(CI) m/z 259/261 (M+l) ⁺ .

3- (4-Formyl-2-hydroxyphenoxy) -propyl nitrate

A solution of 4- (3-bromopropoxy) -3-hydroxybenzaldehyde

(0.50 g, 1.93 mmol) and AgNO ₃ (0.82 g, 4.82 mmol) in CH ₃ CN

(15 mL) was stirred at 70 ⁰ C for 16 hours. Then brine was added to precipitate the excess of AgNO ₃ , the mixture was filtered through Celite and concentrated under reduced pressure. The residue was treated with CH2CI2 (50 mL) and H ₂ O

(50 mL) . After separation, the aqueous layer was extracted twice with EtOAc (10 mL) . The combined organic layers were dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was used without any purification as orange oil (0.41 g) .

Yield: 89%.

¹ H-NMR (CDCl ₃ ) δ 2.33 (2H, qi) , 4.25 (2H, t) , 4.67 (2H, t) , 5.76 (IH, s) , 6.96 (IH, d, Arom) , 7.42-7.47 (2H, m,

Arom) , 9.85 (IH, s) . ¹³ C-NMR (CDCl ₃ ) δ 26.9, 65.3, 69.6,

111.1, 114.7, 124.4, 131.1, 146.1, 150.5, 191.0. MS (CI) m/z

242 (M+l) ⁺ .

5-Formyl-2- [ (nitrooxy)propoxy] -phenyl-3- [ (tert- butoxycarbonyl) amino] propanoate

To a solution of Boc-β-Ala (0.24 g; 1.29 mmol) in dry CH ₂ Cl ₂ (15 mL) , stirred under inert atmosphere, EDC-HC1 (0.55 g; 2.84 mmol) and DMAP (0.03 g; 0.13 mmol) were added. After 1 hour 3- (4-formyl-2-hydroxyphenoxy) -propyl nitrate (0.24 g; 0.97 mmol) was added. The reaction was completed after one night. The mixture was washed with H ₂ O (20 mL) . The organic layer was dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 80/20 v/v) to give the title compound as pale yellow oil (0.26 g) .

Yield: 67%.

¹ H-NMR (CDCl ₃ ) δ 1.44 (s, 9H) , 2.25 (qri, 2H) 2.84 (t, 2H) , 3.52 (d, 2H) , 4.21 (t, 2H) , 4.62 (t, 2H) , 5.11 (s br, IH, NH) , 7.08 (d, IH, Arom) , 7.62 (s, IH, Arom) , 7.78 (d, IH, Arom) , 9.87 (s, IH) . ¹³ C-NMR (CDCl ₃ ) δ 27.2, 28.7, 42.6, 60.8, 65.3, 70.0, 111.5, 113.1, 123.7, 130.7, 130.8, 140.4, 155.3, 156.1, 168.7, 190.2. MS (CI) m/z 413 (M+l) ⁺ . 3- ({3- [ (tert-Butoxycarbonyl) amino] propanoyl}oxy) -4- [ (nitrooxy)propoxy] benzoic acid

KMnO _Λ acetone

KMnO ₄ (0.1 g, 0.65 mmol) was added to a solution of 5- formyl-2- [ (nitrooxy) propoxy] -phenyl-3- [ (tert- butoxycarbonyl) amino] propanoate (0.18 g, 0.43 mmol) in acetone (10 mL) , stirred at 0 ⁰ C. The reaction was allowed to reach r.t. and it was completed after Ih (TLC detection, eluent PE/EtOAc 80/20 v/v) . Oxalic acid was added and the mixture was filtered. The filtrate was diluted with CH2CI2

(20 mL) , the organic layer was washed with H ₂ O (20 mL) , dried with MgSO ₄ , filtered and concentrated under reduced pressure to give the title compound as white solid (0.17 g) . Yield: 85%.

¹ H-NMR (CDCl ₃ ) δ 1.46 (9H, s) , 2.25 (2H, qi) , 2.84 (2H, t) , 3.53 (2H, m) , 4.20 (2H, t) , 4.62 (2H, t) , 5.08 (IH, s) , 7.00 (IH, d, Arom) , 7.80 (IH, s, Arom) , 8.00 (IH, d, Arom) . ¹³ C-NMR (DMSO-de) δ 26.0, 28.1, 33.9, 36.0, 64.9, 70.5, 77.8, 113.0, 123.3, 124.0, 128.7, 138.9, 153.5, 155.5, 166.3, 169.3, 172.8, 192.4. MS (CI) m/z 429 (M+l) ⁺ .

{ [2- (Acetyloxy) benzoyl] oxy}methyl-3- ({3- [tert- butoxycarbonyl) amino]propanoyl}oxy-4- [3- (nitrooxy) propoxy] benzoate

To a solution of chloromethyl 2- (acetyloxy) benzoate (0.57 g, 2.52 mmol) in DMF (8 mL) were added 3- ( { 3- [ ( tert- butoxycarbonyl) amino] propanoyl } oxy) -4- [ (nitrooxy) propoxy] benzoic acid (1.08 g, 2.52 mmol) and CS2CO3 (0.41 g, 1.26 mmol) . The mixture was stirred for one night, then was poured in H2O (30 mL) and extracted with EtOAc (3 x 5 mL) . The combined organic layers were dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 90/10 to 70/30 v/v) to give the title compound as colourless oil (0.83 g) . Yield: 70%. 1H-NMR (CDCl ₃ ) δ 1.45 (9H, s) , 2.23 (2H, qi) , 2.35 (3H, s) , 2.82 (2H, t) , 3.49-3.55 (2H, m) , 4.18 (2H, t) , 4.60 (2H, t) , 5.06 (IH, s) , 6.16 (2H, s) , 6.99 (IH, d, Arom) , 7.10

(IH, d, Arom), 7.33 (IH, t, Arom), 7.59 (IH, t, Arom), 7.80

(IH, s, Arom), 8.00 (IH, d, Arom), 8.08 (IH, d, Arom) . ¹³ C-

NMR (CDCl ₃ ) δ 14.2, 21.0, 26.8, 28.4, 34.5, 60.4, 64.7, 69.3, 79.8, 112.4, 122.0, 124.0, 124.9, 126.2, 129.9, 132.3, 134.7, 139.2, 151.1, 154.3, 155.7, 163.1, 164.0, 169.7, 171.2. MS (CI) m/z 621 (M+l) ⁺ . { [2- (Acetyloxy) benzoyl] oxy}methyl 3- (α-alanyloxy) -4- [3- (nitrooxy) propoxy] benzoate hydrochloride

A solution of { [2- (acetyloxy) benzoyl] oxyjmethyl 3- ( { 3- [ tert- butoxycarbonyl) amino] propanoyl } oxy-4- [3-

(nitrooxy) propoxy] benzoate (1.26 g; 2.00 mmol) in dry dioxane/HCl 2.36 M (12.6 mL, 29.0 mmol), was stirred under inert atmosphere for 3 hours. The mixture was concentrated under reduced pressure. The crude product was tritured with dry Et2<0 to give the title compound as white solid. Yield: 89%. m.p. : 94.5-95.5 ⁰ C 1H-NMR (CDCl ₃ ) δ 2.16 (2H, qi) , 2.25 (3H, s) , 3.03 (2H, m) , 3.12 (2H, m) , 4.21 (2H, t) , 4,63 (2H, t) , 5.60 (IH, m) , 6.14 (2H, s) , 7.27 (IH, d, Arom) , 7.33 (IH, d, Arom) , 7.42 (IH, t, Arom), 7.74 (IH, t, Arom), 7.76 (IH, s, Arom), 7.93- 8.00 (2H, m Arom), 8.22 (s vvbr, 2H) . ¹³ C-NMR (CDCl ₃ ) δ 21.0, 26.6, 31.0, 35.5, 65.0, 70.1, 80.0, 112.4, 121.7, 122.0, 124.0, 124.8, 126.2, 129.9, 132.3, 134.7, 139.1, 151.0, 154.4, 163.1, 164.1, 169.0, 169.7. Example 3

{ [2- (Acetyloxy) benzoyl] oxy}methyl 3- (morpholin-4-yl- methyl) -4- [3- (nitrooxy)propoxy]benzoate oxalate: compound (3) . Methyl 4- (3-bromopropoxy) -3- (morpholin-4-yl- methyl) benzoate

To a solution of methyl 4-hydroxy-3- (morpholin-4-yl- methyl) benzoate (2.00 g, 7.90 mmol) in CH ₃ CN (12 mL) K ₂ CO ₃ (1.66 g, 12.0 mmol) and 1, 3-dibromopropane (3.96 mL, 39.0 mmol) were added, then the mixture was heated at reflux for 6 hours. Thereafter the cooled reaction mixture was poured in H ₂ O (50 mL) and extracted with EtOAc (3 x 50 mL) . The combined organic layers were washed with H ₂ O (25 mL) , brine (25 mL) , dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 60/40 v/v) to give the title compound (1.12 g) as colourless oil. Yield: 38%. 1H-NMR (CDCl ₃ ) δ 2.36 (2H, qi) , 2.48 (4H, t) , 3.53 (2H, s) , 3.64-3.73 (6H, m) , 3.89 (3H, s) , 4.19 (2H, t) , 6.90 (IH, d, Arom) , 7.94 (IH, d, Arom) , 8.01 (IH, s, Arom) . ¹³ C-NMR (CDCl ₃ ) δ 29.8, 32.2, 51.9, 53.7, 56.7, 65.5, 67.0, 110.8, 122.4, 126.1, 130.6, 132.3, 160.6, 166.9.

Methyl 3- (morpholin-4-yl-methyl) -4- [3- (nitrooxy) propoxy] benzoate

A solution of methyl 4- (3-bromopropoxy) -3- (morpholin-4- yl-methyl)benzoate (1.12 g, 3.00 mmol) and AgNO ₃ (0.54 g, 3.2 mmol) in CH ₃ CN (10 mL) was stirred at 70 ⁰ C for 3 h. Then brine was added to precipitate the excess of AgNO ₃ , the mixture was filtered through Celite and concentrated under reduced pressure. The residue was treated with CH2CI2 (50 mL) and H ₂ O (25 mL) . After separation, the aqueous layer was extracted twice with CH ₂ Cl ₂ (50 mL) . The combined organic layers were dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 60/40 v/v) to give the title compound (0.81 g) as colourless oil.

Yield: 75%.

¹ H-NMR (CDCl ₃ ) δ 2.27 (2H, qi) , 2.49 (4H, m) , 3.53 (2H, s) , 3.70 (4H, m) , 3.89 (3H, s) , 4.15 (2H, t) , 4.72 (2H, t) , 6.87 (IH, d, Arom) , 7.94 (IH, d, Arom) , 8.02 (IH, s, Arom) . ¹³ C-NMR (CDCl ₃ ) δ 27.0, 51.9, 53.7, 56.7, 63.9, 67.0, 69.8, 110.7, 122.6, 126.1, 130.6, 132.4, 160.4, 166.9.

3- (Morpholin-4-yl-methyl) -4- [3- (nitrooxy)propoxy] benzoic acid

A solution of methyl 3- (morpholin-4-yl-methyl) -4- [3-

(nitrooxy) propoxy] benzoate (0.81 g, 2.29 mmol) in MeOH (10 mL) and IN NaOH (4 mL) was stirred at room temperature for 4 h. Then the solvent was removed under reduced pressure, the residue was dissolved in H ₂ O (15 mL) , the pH adjusted to 7 and the product was extracted in continuous for 18 hours with EtOAc The EtOAc layer was dried with MgSO ₄ , filtered and concentrated under reduced pressure to give the title compound (0.52 g) as colourless oil.

Yield: 67%.

¹ H-NMR(CDCl ₃ ) δ 2.28 (2H, qi) , 2.79 (4H, m) , 3.77 (4H, m) , 3.85 (2H, s) , 4.21 (2H, t) , 4.74 (2H, t) , 7.07 (IH, d, Arom) , 7.98 (IH, d, Arom) , 8.04 (IH, s, Arom) . ¹³ C-NMR (CDCl ₃ ) δ 28.0, 54.2, 57.1, 66.1, 66.9, 71.9, 112.2, 123.7, 126.4, 133.0, 134.7, 161.8, 171.0.

{ [2- (Acetyloxy) benzoyl] oxy}methyl 3- (morpholin-4-yl- methyl) -4- [3- (nitrooxy) propoxy] benzoate oxalate

To a solution of 3- (morpholin-4-yl-methyl) -4- [3-

(nitrooxy) propoxy] benzoic acid (0.56 g, 1.64 mmol) in DMF (6 mL) were added Cs ₂ CO ₃ (0.27 g, 0.8 mmol) and after 10 min chloromethyl 2- (acetyloxy) benzoate (0.38 g, 1.64 mmol) . The mixture was stirred for 24 hours, then was poured in H ₂ O (15 mL) and extracted with EtOAc (3 x 50 mL) . The combined organic layers were washed with H ₂ O (20 mL) , brine (20 mL) , dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 60/40 v/v) to give the { [2-

( acetyloxy) benzoyl] oxy } methyl 4- (morpholin-4-yl-methyl) -3-

[3- (nitrooxy) propoxy] benzoate (0.38 g) as colourless oil. To a solution of { [2- (acetyloxy) benzoyl] oxy jmethyl 4- (morpholin-4-yl-methyl) -3- [ 3- (nitrooxy) propoxy] benzoate in EtOAc (3 mL) was added a solution of H ₂ C ₂ O ₄ (0.06 g, 1 eq) in EtOAc (2 mL) and the title compound (0.17 g) was obtained by filtration as white solid. Yield: 20%. 1H NMR (DMSO-de) δ 2.17-2.25 (5H, m) , 2.71 (4H, m) , 3.64

(4H, m) , 3.83 (2H, s) , 4.20 (2H, t) , 4.74 (2H, t) , 6.14 (2H, s) , 7.19 (IH, d, Arom) , 7.27 (IH, d, Arom) , 7.42 (IH, t,

Arom) , 7.73 (IH, t, Arom), 7.96-8.05 (3H, m, Arom), 8.06

(IH, s) . ¹³ C NMR (DMSO-de) δ 20.9, 26.3, 52.7, 54.9, 65.2, 65.3, 71.3, 80.5, 112.2, 120.5, 122.2, 124.5, 126.7, 131.8, 132.1, 133.2, 135.4, 150.5, 161.6, 162.6, 163.1, 164.3, 169.3.

Example 4 { [2- (Acetyloxy) benzoyl] oxy}methyl 3- (β-alanyloxy) -4- [4- (nitrooxy)butoxy] benzoate hydrochloride: compound (4) . 4- (4-Chlorobutoxy) -3-hydroxybenzaldehyde

A s o lut i on o f 3 , 4 -dihydroxy-ben z aldehyde ( 1 . 0 0 g , 7 . 24 mmol) , l-bromo-4-chlorobutane (2.50 mL, 21.7 mmol) and KHCO3 (0.87 g, 8.69 mmol) in CH ₃ CN (20 mL) was stirred a r.t. for 14 hours. Then the mixture was poured in H ₂ O (30 mL) and extracted twice with EtOAc (30 mL) ; the combined organic layers were washed with brine (10 mL) , dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 85/15 to 60/40 v/v) to give the title compound (1.03 g) as white solid.

Yield: 60%.

¹ H-NMR (CDCl ₃ ) δ 1.95-2.12 (4H, m) , 3.64 (2H, t) , 4.20 (2H, t) , 5.93 (IH, s) , 6.97 (IH, d, Arom) , 7.41-7.46 (2H, m, Arom) , 9.83 (IH, s) . ¹³ C-NMR (CDCl ₃ ) δ 26.9, 29.6, 45.0, 68.9, 111.4, 114.8, 125.0, 131.2, 146.7, 151.6, 191.6. MS (CI) m/z 229/231 (M+l) ⁺ .

4- (4-Formyl-2-hydroxyphenoxy) butyl nitrate

A solution of 4- (4-chlorobutoxy) -3-hydroxybenzaldehyde (1.00 g, 4.37 mmol) and AgNO ₃ (1.86 g, 10.93 mmol) in CH ₃ CN (25 mL) was stirred at 70 ⁰ C for 14h. Then brine was added to precipitate the excess of AgNO ₃ , the mixture was filtered through Celite and concentrated under reduced pressure. The residue was treated with CH ₂ Cl ₂ (50 mL) and H ₂ O (50 mL) . After separation, the aqueous layer was extracted twice with EtOAc (10 mL) . The combined organic layers were dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was used without any purification as yellow solid (0.73 g) . Yield: 63%.

¹ H-NMR (CDCl ₃ ) δ 1.95-2.04 (4H, m) , 4.19 (2H, t) , 4.55

(2H, t) , 5.74 (IH, s) , 6.97 (IH, d, Arom) , 7.45 (2H, m,

Arom) , 9.85 (IH, s) . ¹³ C-NMR (CDCl ₃ ) δ 23.7, 25.5, 68.2,

72.5, 111.0, 114.4, 124.5, 130.8, 146.1, 150.9, 191.1. MS

(CI) m/z 256 (M+l) ⁺ .

5-Formyl-2- [ (nitrooxy)butoxy] -phenyl-3- [ (tert- butoxycarbonyl) amino] propanoate

drv

To a solution of Boc-β-Ala (0.19 g; 1.01 mmol) in dry CH ₂ Cl ₂ (15 mL) , stirred under inert atmosphere, EDC-HC1 (0.25 g; 1.32 mmol) and DMAP (0.02 g; 0.08 mmol) were added. After 1 h 4- (4-formyl-2-hydroxyphenoxy) butyl nitrate (0.20 g; 0.78 mmol) was added. The reaction was completed after one night. The mixture was washed with H ₂ O (20 mL) . The organic layer was dried, filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 80/20 v/v) to give the title compound as pale yellow oil (0.16 g) . Yield: 48%. ¹ H-NMR (CDCl ₃ ) δ 1.28 (s, 9H), 1.89-1.97 (m, 4H), 2.83 (t, 2H), 3.50-3.56 (m, 2H), 4.13 (t, 2H), 4.53 (t, 2H), 5.02 (m, IH), 7.06 (d, IH, Arom) , 7.61 (s, IH, Arom) , 7.76 (d, IH, Arom), 9.87 (s, IH) . ¹³ C-NMR (CDCl ₃ ) δ 23.6, 25.3, 28.4, 34.5, 36.2, 68.1, 72.5, 112.7, 123.5, 130.1, 130.2, 140.1, 155.2, 155.8, 170.1, 182.1, 189.9. MS (CI) m/z 427 (M+l) ⁺ .

3- ({3- [ (tert-Butoxycarbonyl) amino] propanoyl}oxy) -4- [ (nitrooxy)butoxy] benzoic acid

KMnO ₄ (0.10 g, 0.65 mmol) was added to a solution of 5- formyl-2- [ (nitrooxy) butoxy] -phenyl-3- [ (tert- butoxycarbonyl) amino] propanoate (0.18 g, 0.43 mmol) in acetone (10 mL) , stirred at 0 ⁰ C. The reaction was allowed to reach r.t. and it was completed after Ih (TLC detection, eluent PE/EtOAc 80/20 v/v) . Oxalic acid was added and the mixture was filtered. The filtrate was diluted with CH2CI2 (20 mL) , the organic layer was washed with H2O (20 mL) , dried with MgSO ₄ , filtered and concentrated under reduced pressure to give the title compound as white solid (0.10 g) . Yield: 90%. 1H-NMR (DMSO-de) δ 1.39 (9H, s) , 1.79 (4H, m) , 2.71 (2H, t) , 3.29 (2H, m) , 4.01 (2H, t) , 4.57 (2H, t) , 6.98 (IH, m) , 7.21 (IH, d, Arom), 7.68 (IH, s, Arom), 7.83 (IH, d, Arom), 12.8 (IH, sbr) . ¹³ C-NMR (DMSO-d ₆ ) δ 22.7, 24.6, 28.1, 33.9, 36.0, 67.7, 73.3, 77.7, 113.0, 117.0, 123.0, 128.7, 138.8, 153.7, 155.4, 166.3, 169.2. MS (CI) m/z 443 (M+l) ⁺ . { [2- (Acetyloxy) benzoyl] oxyjmethyl- 3- ({3- [tert- butoxycarbonyl) amino]propanoyl}oxy-4- [3- (nitrooxy) butoxy] benzoate

To a solution of chloromethyl 2- (acetyloxy) benzoate (0.05 g, 0.24 mmol) in DMF (3 mL) were added 3- ( { 3- [ ( tert- butoxycarbonyl) amino] propanoyl } oxy) -4- [ (nitrooxy) butoxy] benzoic acid (0.10 g, 0.24 mmol) and Cs ₂ CO ₃ (0.04 g, 0.12 mmol) . The mixture was stirred for one night, then was poured in H ₂ O (30 mL) and extracted with EtOAc (3 x 5 mL) . The combined organic layers were dried with MgSθ4, filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 90/10 to 70/30 v/v) to give the title compound as colourless oil (0.07 g) .

Yield: 45%.

¹ H-NMR (CDCl ₃ ) δ 1.46 (9H, s) , 1.93 (4H, s) , 2.37 (3H, s) , 2.83 (2H, t) , 3.53 (2H, q) , 4.13 (2H, t) , 4.53 (2H, t) , 5.10 (IH, sbr) , 6.18 (2H, s) , 6.99 (IH, d, Arom) , 7.15 (IH, d, Arom), 7.36 (IH, t, Arom), 7.61 (IH, t, Arom), 7.81 (IH, s) 7.99 (IH, d, Arom), 8.01 (IH, d) . ¹³ C-NMR (CDCl ₃ ) δ 21.0, 23.6, 25.3, 28.4, 34.5, 36.1, 51.7, 67.9, 72.5, 79.8, 86.7,

112.3, 121.7, 122.0, 124.0, 124.9, 126.1, 129.9, 132.3,

134.7, 139.3, 143.7, 151.1, 154.6, 155.7, 155.8, 163.1,

164.1, 170.1. MS (CI) m/z 635 (M+l) ⁺ .

{ [2- (Acetyloxy) benzoyl] oxy}methyl 3- (β-alanyloxy) -4- [4- (nitrooxy) butoxy] benzoate hydrochloride

Dioxane _H

A solution of { [2- (acetyloxy) benzoyl] oxy jmethyl- 3-({3- [ tert-butoxycarbonyl) amino] propanoyl}oxy-4- [3- (nitrooxy) butoxy] benzoate (250 mg; 0.39 mmol) in dry/HCl 2.36 M in dioxane (2.5 mL; 5.91 mmol) was stirred under inert atmosphere. The reaction was completed after 4 hours. The mixture was concentrated under reduced pressure. The crude product was purified by flash chromatography (H ₂ O/CH ₃ CN/TFA 60/40/0.1 v/v/v) to give the title compound as colourless oil .

Yield: 50%.

¹ H-NMR (DMSO-de) δ 1.88 {m, 3H), 2.56 (qri, 2H), 3.10 (t, 2H), 3.19 (t, 2H), 3.46 {m, 2H), 4.12 (t, 2H), 4.58 (t, 2H),

6.14 (s, 2H), 7.17-7.21 (m, 2H, Arom) , 7.42 (t, IH, Arom) , 7.66 (t, IH, Arom) , 7.80 (s, IH, Arom) , 7.94-8.03 (m, 2H,

Arom) 7.95-8.34 (2H, svvbr, , NH ₂ ) . ¹³ C-NMR (DMSO-d ₆ ) δ 21.4,

23.8, 25.5, 31.9, 35.4, 68.7, 73.7, 80.6, 113.7, 121.4,

122.7, 124.7, 125.0, 126.9, 130.3, 132.3, 135.5, 139.6, 151.2, 155.4, 163.4, 164.3, 169.0, 169.7.

Example 5

{ [2- (Acetyloxy) benzoyl] oxyjmethyl 3- (glycyloxy) -4- [3- (nitrooxy)propoxy]benzoate hydrochloride: compound (5) . 5-Formyl-2- [ (nitrooxy)propoxy] -phenyl-3- [ (tert- butoxycarbonyl) amino] acetate

dry

To a solution of [( tert-butoxycarbonyl) amino] acetic acid ¹⁶ (0.14 g; 0.83 mmol) in dry CH ₂ Cl ₂ (15 mL) , stirred under inert atmosphere, EDC-HC1 (0.20 g; 1.03 mmol) and DMAP (0.01 g; 0.08 mmol) were added. After 1 hour 3- (4-formyl-2- hydroxyphenoxy) -propyl nitrate (0.20 g; 0.83 mmol) was added. The reaction was completed after one night. The mixture was washed with H ₂ O (20 mL) . The organic layer was dried, filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 80/20 v/v) to give the title compound as pale yellow oil (0.11 g) .

Yield: 50%.

¹ H-NMR (CDCl ₃ ) δ 1.47 (9H, s) , 2.27 (2H, qi) , 4.08-4.27

(4H, m) , 4.63 (2H, t) , 5.09 (IH, m) , 7.07 (IH, d, Arom) ,

7.61 (IH, s, Arom), 7.77 (IH, d, Arom), 9.88 (IH, s) . ¹³ C-

NMR (CDCl ₃ ) δ 28.7, 42.6, 60.8, 65.3, 70.0, 111.5, 113.1,

123.7, 130.7, 130.8, 140.4, 155.3, 156.1, 168.7, 190.2. MS

(CI) m/z 399 (M+l) ⁺ .

3- ({3- [ (tert-Butoxycarbonyl) amino] acetoxy} ) -4- [ (nitrooxy)propoxy] benzoic acid

KMnO ₄ (0.06 g, 0.37 mmol) was added to a solution of 5- formyl-2- [ (nitrooxy) propoxy] -phenyl-3- [ (tert- butoxycarbonyl) amino] acetate (0.10 g, 0.25 mmol) in acetone

(5mL) , stirred at 0 ⁰ C. The reaction was allowed to reach r.t. and it was completed after Ih (TLC detection, eluent PE/EtOAc 80/20 v/v) . Oxalic acid was added and the mixture was filtered and the filtrate was diluted with CH ₂ Cl ₂ (20 mL) . The organic layer was washed with H ₂ O (20 mL) , then was dried with MgSO ₄ , filtered and concentrated under reduced pressure to give the title compound as white solid (0.05 g) . Yield 50%. 1H-NMR (DMSO-de) δ 1.40 (s, 9H), 2.09-2.16 (m, 2H), 4.00

(m, 2H), 4.17 (t, 2H), 4.65 (t, 2H), 7.26 (d, IH, Arom), 7.61 (s, IH, Arom), 7.87 (d, IH, Arom), 12.0 (IH, sbr) . ¹³ C- NMR (DMSO-de) δ 26.9, 28.9, 42.5, 65.7, 71.5, 79.3, 85.2, 114.1, 124.2, 129.8, 139.7, 154.4, 156.7, 161.9, 167.1, 169.6 198.9. MS (CI) m/z 415 (M+l) ⁺ .

{ [2- (Acetyloxy) benzoyl] oxyjmethyl- 3- ({3- [tert- butoxycarbonyl) amino] acetoxy} -4- [3- (nitrooxy) propoxy] benzoate

To a solution of chloromethyl 2- (acetyloxy) benzoate (0.07 g, 0.30 mmol) in DMF (5 mL) were added 3- ( { 3- [ ( tert- butoxycarbonyl) amino] acetoxy}) -4- [(nitrooxy) propoxy] benzoic acid (0.13 g, 0.30 mmol) and Cs ₂ CO ₃ (0.05 g, 0.15 mmol) . The mixture was stirred for one night, then was poured in H ₂ O

(30 mL) and extracted with EtOAc (3 x 5 mL) . The combined organic layers were dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 80/20 to 60/40 v/v) to give the title compound as colourless oil (0.13 g) . Yield: 70%. 1H-NMR (CDCl ₃ ) δ 1.46 (9H, s) , 2.23 (2H, qi) , 2.53 (3H, s) , 4.08-4.21 (4H, m) , 4.63 (2H, t) , 5.06 (IH, s) , 6.16 (2H, s) , 6.98 (IH, d, Arom) , 7.11 (IH, d, Arom) , 7.32 (IH, t, Arom) , 7.59 (IH, t, Arom), 7.80 (IH, s, Arom), 8.00 (IH, d, 13,

Arom) , 8.08 (IH, d, Arom) . ^1J C-NMR (CDCl ₃ ) δ 14.2, 21.0, 26.9, 28.3, 42.1, 60.4, 64.6, 69.7, 79.8, 85.4, 112.4, 121.9, 123.3, 124.0, 124.7, 130.0, 132.3, 134.6, 139.1, 151.1, 154.4, 155.7, 163.1, 164.0, 168.3, 169.7, 189.8. MS (CI) m/z 607 (M+l) ⁺ .

{ [2- (Acetyloxy) benzoyl] oxy}methyl 3- (glycyloxy) -4- [3- (nitrooxy) propoxy] benzoate hydrochloride

A solution of { [2- (acetyloxy) benzoyl] oxy jmethyl- 3-({3-

[ tert-butoxycarbonyl) amino] acetoxy}-4- [3- (nitrooxy) propoxy] benzoate (300 mg; 0.50 mmol) in dry dioxane/HCl 2.36 M (3, 2 mL; 7.42 mmol) was stirred under inert atmosphere for 3 hours. The mixture was concentrated under reduced pressure. The crude product was purified by flash chromatography (H ₂ O/CH ₃ CN/HC1 60/40/0.1 v/v) to give the title compound as white solid. Yield: 40%. m.p.: 60.5-62.5 ⁰ C 1H-NMR (CDCl ₃ ) δ 2.16 (m, 2H), 2.31 (s, 3H), 4.00 (m, 2H), 4.20 (t, 2H), 4.53 (t, 2H), 6.13 (s, 2H), 6.83 (d, IH, Arom) , 7.08 (d, IH, Arom) , 7.27 (t, IH, Arom) , 7.55 (t, IH, Arom) , 7.68 (s, IH, Arom), 7.86 (d, IH, Arom), 8.03 (d, IH, Arom), 8.70 (2H, svvbr) .

Example 6

{ [2- (Acetyloxy) benzoyl] oxy}methyl 3- (alanyloxy) -4- [3- (nitrooxy)propoxy]benzoate hydrochloride: compound (6) . 5-Formyl-2- [ (nitrooxy)propoxy] -phenyl-2- [ (tert- butoxycarbonyl) amino] propanoate

To a solution of Boc-alpha-Ala (0.16 g; 0.83 mmol) in dry CH ₂ Cl ₂ (15 mL) , stirred under inert atmosphere, EDC-HCl (0.20 g; 1.03 mmol) and DMAP (0.01 g; 0.08 mmol) were added. After 1 hour 3- (4-formyl-2-hydroxyphenoxy) -propyl nitrate (0.20 g; 0.83 mmol) was added. The reaction was completed after one night. The mixture was washed with H ₂ O (20 mL) . The organic layer was dried, filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 70/30 v/v) to give the title compound as pale yellow solid (0.25 g) .

Yield: 65%.

¹ H-NMR (CDCl ₃ ) δl.47 (9H, s) , 1.57 (3H, d) , 2.25 (2H, qi) , 4.19 (2H, t) , 4.64 (2H, t) , 5.05 (IH, m) , 7.07 (IH, d, Arom), 7.62 (IH, s, Arom), 7.77 (IH, d, Arom), 9.88 (IH, s) .

¹³ C-NMR (CDCl ₃ ) δ 18.5, 26.8, 28.3, 49.2, 64.6, 64.8, 69.4, 99.0, 100.7, 112.7, 123.4, 130.2, 130.3, 140.0, 155.0, 189.8. MS (CI) m/z 413 (M+l) ⁺ . 3- ({2- [ (tert-Butoxycarbonyl) amino] propanoyl}oxy) -4- [ (nitrooxy)propoxy] benzoic acid

KMnO ₄ (0.14 g, 0.87 mmol) was added to a solution of 5- formyl-2- [ (nitrooxy) propoxy] -phenyl-2- [ (tert- butoxycarbonyl) amino] propanoate (0.24 g, 0.58 mmol) in acetone (8 mL) , stirred at 0 ⁰ C. The reaction was allowed to reach r.t. and it was completed after Ih (TLC detection, eluent PE/EtOAc 70/30 v/v) . Oxalic acid was added and the mixture was filtered. The filtrate was diluted with CH2CI2

(20 mL) , the organic layer was washed with H2O (20 mL) , dried with MgSO ₄ , filtered and concentrated under reduced pressure to give the title compound as white solid (0.18 g) .

Yield: 80%. 1H-NMR (DMSO-de) δ 1.40 (12H, s) , 2.12 (2H, qi) , 4.16 (2H, t) , 4.23 (IH, m) , 4.64 (2H, t) , 7.23 (IH, d, Arom) , 7.55 (IH, m, Arom), 7.89 (IH, d, Arom) . ¹³ C-NMR (DMSO-d ₆ ) δ 16.6, 25.9, 28.1, 49.0, 64.8, 70.4, 78.3, 113.1, 123.2, 123.5, 128.8, 138.7, 153.5, 155.2, 166.2, 171.2. MS (CI) m/z 429 (M+l) ⁺ .

{ [2- (Acetyloxy) benzoyl] oxy}methyl-3- ({2- [tert- butoxycarbonyl) amino]propanoyl}oxy-4- [3- (nitrooxy) propoxy] benzoate

To a solution of chloromethyl 2- (acetyloxy) benzoate (0.09 g, 0.40 mmol) in DMF (5 mL) were added 3- ( { 2- [ ( tert- butoxycarbonyl) amino] propanoyl } oxy) -4- [ (nitrooxy) propoxy] benzoic acid (0.17 g, 0.40 mmol) and CS2CO3 (0.06 g, 0.20 mmol) . The mixture was stirred for one night, then was poured in H ₂ O (30 mL) and extracted with EtOAc (3 x 5 mL) . The combined organic layers were dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 80/20 to 70/30 v/v) to give the title compound as colourless oil (0.13 g) .

Yield: 50%.

¹ H-NMR (CDCl ₃ ) δ 1.46 (9H, s) , 1.57 (3H, d) , 2.22 (2H, qi) , 2.35 (3H, s) , 3.50 (IH, svvbr) 4.16 (2H, t) , 4.63 (2H, t) , 6.16 (2H, s) , 6.98 (IH, d, Arom) , 7.11 (IH, d, Arom) , 7.33 (IH, t, Arom) , 7.57 (IH, t, Arom) , 7.80 (IH, s, Arom) , 7.99 (IH, d, Arom) , 8.07 (IH, d, Arom) . ¹³ C-NMR (CDCl ₃ ) δ 18.6, 20.4, 21.0, 26.8, 28.3, 64.6, 69.5, 79.8, 112.4, 121.9, 124.0, 124.7, 125.0, 126.1, 129.8, 130.0, 131.2, 132.3, 134.7, 139.2, 143.2, 151.1, 154.4, 163.1, 164.0, 164.1, 168.1, 168.5, 169.7. MS (CI) m/z 620 (M+l) ⁺ .

{ [2- (Acetyloxy) benzoyl] oxyjmethyl 3- (alanyloxy) -4- [3- (nitrooxy) propoxy] benzoate hydrochloride

A solution of { [2- (acetyloxy) benzoyl] oxy }methyl-3- ({ 2- [ tert-butoxycarbonyl) amino] propanoyl}oxy-4- [3- (nitrooxy) propoxy] benzoate (280 mg; 0.45 mmol) in dry dioxane/HCl 2.36 M (3 mL; 6.65 mmol) was stirred under inert atmosphere for 3 h. The mixture was concentrated under reduced pressure. The crude product was purified by flash chromatography (H ₂ O/CH ₃ CN/HC1 80/20/0.1 v/v to 60/40/0.1) to give the title compound as white solid.

Yield: 44%. m.p.: 65.5-69.0 ⁰ C

¹ H-NMR (CDCl ₃ ) δ 1.71 (d, 3H), 2.04 (qi, 2H), 2.25 (s, 3H), 3.96 (t, 2H), 4.33 (m, IH), 4.46 (t, 2H), 6.05 (s, 2H), 6.77 (d, IH, Arom) , 7.03 (d, IH, Arom) , 7.24 (t, IH, Arom) ,

7. ;t, IH Arom, 7.77 (s, IH, Arom), 7.86 (d, IH, Arom),

8.03 (d, IH, Arom) , 8.84 (2H, swixr) . ¹³ C-NMR (CDCl ₃ ) δ 16.1,

21.0, 26.6, 53.1, 65.1, 70.1, 85.7, 112.4, 121.6, 122.0,

124.0, 124.4, 126.2, 130.3, 132.2, 134.7, 138.5, 151.0, 154.2, 163.0, 163.9, 167.8, 169.7. Example 7

{ [2- (Acetyloxy) benzoyl] oxy}methyl 3- (alanyloxy) -4- [4- (nitrooxy)butoxy]benzoate hydrochloride: compound (7) . 5-Formyl-2- [ (nitrooxy)butoxy] -phenyl-2- [ (tert- butoxycarbonyl) amino] propanoate

To a solution of Boc-alpha-Ala (0.19 g; 1.02 mmol) in dry CH ₂ Cl ₂ (15 mL) , stirred under inert atmosphere, EDC-HC1 (0.25 g; 1.32 mmol) and DMAP (0.01 g; 0.08 mmol) were added. After I h 4- (4-formyl-2-hydroxyphenoxy) butyl nitrate (0.20 g; 0.78 mmol) was added. The reaction was completed after one night. The mixture was washed with H ₂ O (20 mL) . The organic layer was dried, filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 80/20 to 70/30 v/v) to give the title compound as pale yellow solid (0.10 g) . Yield: 64%.

¹ H-NMR (CDCl ₃ ) δl.47 (9H, s) , 1.57 (3H, d) , 1.92 (4H, m) , 4.12 (2H, t) , 4.51 (2H, t) , 4.52 (IH, m) , 5.03(1H, m) , 7.04 (IH, d, Arom) , 7.61 (IH, s, Arom) , 7.77 (IH, d, Arom) , 9.87 (IH, s) . ¹³ C-NMR (CDCl ₃ ) δ 18.6, 23.6, 25.4, 27.8, 49.2, 60.4, 68.1, 72.6, 112.7, 123.5, 130.1, 130.2, 139.9, 155.1, 155.3, 171.2, 189.9. MS (CI) m/z 427 (M+l) ⁺ .

3- ({2- [ (tert-Butoxycarbonyl) amino] propanoyl}oxy) -4- [ (nitrooxy)butoxy] benzoic acid

KMnO ₄ (0.05 g, 0.35 mmol) was added to a solution of 5- formyl-2- [ (nitrooxy) butoxy] -phenyl-2- [ (tert- butoxycarbonyl) amino] propanoate (0.10 g, 0.23 mmol) in acetone (5mL) , stirred at 0 ⁰ C. The reaction was allowed to reach r.t. and it was completed after Ih (TLC detection, eluent PE/EtOAc 70/30 v/v) . Oxalic acid was added and the mixture was filtered. The filtrate was diluted with CH2CI2

(15 mL) , the organic layer was washed with H ₂ O (15 mL) , dried with MgSO ₄ , filtered and concentrated under reduced pressure to give the title compound as white solid (0.07 g) . Yield: 78%.

¹ H-NMR (DMSO-de) δ 1.41 (12H, s) , 1.80 (4H, m) , 4.01 (2H, t) , 4.27(1H, m) , 4.57 (2H, t) , 7.2O(1H, d, Arom) , 7.54 (IH, m, Arom), 7.84 (IH, d, Arom), 12.86 (IH, sbr) . ¹³ C-NMR

(DMSO-d ₆ ) δ 16.6, 22.7, 24.7, 28.1, 49.0, 67.7, 73.3, 78.3,

113.1, 123.0, 123.5, 128.8, 138.7, 153.8, 155.2, 166.2,

171.2. MS (CI) m/z 443 (M+l) ⁺ .

{ [2- (Acetyloxy) benzoyl] oxy}methyl-3- ({2- [tert- butoxycarbonyl) amino]propanoyl}oxy-4- [3- (nitrooxy) butoxy] benzoate

To a solution of chloromethyl 2- (acetyloxy) benzoate (0.08 g, 0.330 mmol) in DMF (5 mL) were added 3- ( { 2- [ ( tert- butoxycarbonyl) amino] propanoyl } oxy) -4-

[ (nitrooxy) butoxy] benzoic acid (0.14 g, 0.33 mmol) and CS ₂ CO ₃ (0.05 g, 0.16 mmol) . The mixture was stirred for one night, then was poured in H ₂ O (30 mL) and extracted with EtOAc (3 x 5 mL) . The combined organic layers were dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 80/20 to 60/40 v/v) to give the title compound as colourless oil (0.10 g) .

Yield: 50%.

¹ H-NMR (CDCl ₃ ) δ 1.46 (9H, s) , 1.57 (3H, d) , 1.91 (4H, m), 2.35 (3H, S) ₁ 4.09 (2H, t) , 4.51 (2H, t) , 4.60 (IH, m) , 5.04 (IH, m) , 6.16 (2H, s) , 6.97 (IH, d, Arom) , 7.11 (IH, d, Arom) , 7.33 (IH, t, Arom), 7.59 (IH, t, Arom), 7.79 (IH, s, Arom) , 7.98 (IH, d, Arom) , 8.08 (IH, d, Arom) . MS (CI) m/z 579 (M-56) ⁺ -

{ [2- (Acetyloxy) benzoyl] oxy}methyl 3- (alanyloxy) -4- [4- (nitrooxy) butoxy] benzoate hydrochloride

Dioxane _HC1

A solution of { [2- (acetyloxy) benzoyl] oxy }methyl-3- ({ 2- [ tert-butoxycarbonyl) amino] propanoyl}oxy-4- [3- (nitrooxy) butoxy] benzoate (140 mg; 0.22 mmol) in dry dioxane/HCl 2.36M (1.44 mL; 3.31 mmol) was stirred under inert atmosphere for 3 hours . The mixture was concentrated under reduced pressure. The crude product was tritured whit dry Et2<0 to give the title compound as white solid (90 mg) .

Yield: 71%. m.p. : 118-119.5 ⁰ C

¹ H-NMR (CDCl ₃ ) δ 1.81 {m, 7H), 2.33 (s, 3H), 3.98 (t,

2H), 4.47 (m, 3H), 6.12 (s, 2H), 6.90 (d, IH, Arom), 7.08

(d, IH, Arom), 7.27 (t, IH, Arom), 7.56 (t, IH Arom,), 7.76

(s, IH, Arom), 7.93 (d, IH, Arom), 8.03 (d, IH, Arom), 8.96 (2H, svvbr) . Example 8

{ [2- (Acetyloxy) benzoyl] oxy}methyl 4- [3-

(nitrooxy) propoxy] -3- (threonyloxy) benzoate hydrochloride : compound (8) .

5-Formyl-2- [ (nitooxy) propoxy] -phenyl-2- [ (tert- butoxycarbonyl) amino] -3- (tetrahydro-2H-pyran-2-yl-- oxy) butanoate

To a solution of Boc-Thr-THP (0.20 g; 0.67 mmol) in dry CH ₂ Cl ₂ (15 mL) , stirred under inert atmosphere, EDC-HC1 (0.16 g; 0.82 mmol) and DMAP (0.01 g; 0.07 mmol) were added. After 1 hour 3- (4-formyl-2-hydroxyphenoxy) -propyl nitrate (0.16 g; 0.67 mmol) was added. The reaction was completed after one night. The mixture was washed with H ₂ O (20 mL) . The organic layer was dried, filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 90/10 to 70/30 v/v) to give the title compound as pale yellow oil (0.20 g) . Yield: 55%. 1H-NMR (CDCl ₃ ) δ 1.31 (2H, d) , 1.41 (2H, d) , 1.47 (9H, s) , 1.55 (4H, m) , 1.63-1.83 (3H, m) , 2.25 (2H, m) , 3.56 (IH, IR) ₁ 3.78-3.96 (IH, m) , 4.16 (2H, t) , 4.53 (IH, m) , 4.66 (2H, t) , 5.30-5.50 (IH, m) , 7.07 (IH, m, Arom) , 7.55 (IH, s, Arom) , 7.76 (IH, d, Arom), 9.86 (IH, s) . ¹³ C-NMR (CDCl ₃ ) δ 14.5, 17.7, 19.2, 25.5, 26.9, 28.3, 30.8, 58.4, 60.4, 63.0, 64.7, 69.5, 71.1, 80.1, 94.7, 96.4, 100.0, 111.1, 112.7, 114.7, 123.2, 130.3, 155.2, 189.9 3- ({3- [ (tert-Butoxycarbonyl) amino] (tetrahydro-2H-pyran-2- yl-oxy)butoxy) -4- [ (nitrooxy)propoxy] benzoic acid

KMnO ₄ (0.08 g, 0.51 mmol) was added to a solution of 5- formyl-2- [ (nitrooxy) propoxy] -phenyl-2- [ (tert- butoxycarbonyl) amino] -3- (tetrahydro-2H-pyran-2-yl- oxy) butanoate (0.18 g, 0.34 mmol) in acetone (5mL) , stirred at 0 ⁰ C. The reaction was allowed to reach r.t. and it was completed after Ih (TLC detection, eluent PE/EtOAc 80/20 v/v) . Oxalic acid was added and the mixture was filtered. The filtrate was diluted with CH2CI2 (15 mL) , the organic layer was washed with H2O (15 mL) , dried with MgSO ₄ , filtered and concentrated under reduced pressure to give the title compound as white solid (0.14 g) . Yield: 73%.

¹ H-NMR (DMSO-de) δ 1.14 (2H, d) , 1.14 (2H, d) , 1.36 (9H, s) , 1.40 (4H, m) , 1.50-1.69 (3H, m) , 2.07 (2H, m) , 3.39 (IH, m), 3.77 (IH, IR) ₁ 4.18 (2H, m) , 4.33 (IH, m) , 4.60 (2H, m) , 7.19 (IH, m, Arom) , 7.49 (IH, s, Arom) , 7.79 (IH, d, Arom) , 12.8 (IH, svvbr) .

{ [2- (Acetyloxy) benzoyl] oxyjmethyl- 3- ({3- [tert- butoxycarbonyl) amino] (tetrahydro-2H-pyran-2-yl-oxy)butoxy) 4- [3- (nitrooxy) propoxy] benzoate o a solution of chloromethyl 2- (acetyloxy) benzoate (0.06 g, 0.25 mmol) in DMF (3 mL) were added 3- ( { 3- [ ( tert- butoxycarbonyl) amino] (tetrahydro-2H-pyran-2-yl-oxy) butoxy) - 4- [ (nitrooxy) propoxy] benzoic acid (0.14 g, 0.25 mmol) and Cs ₂ CO ₃ (0.04 g, 0.13 mmol) . The mixture was stirred for 18 hours, then was poured in H ₂ O (25 mL) and extracted with EtOAc (3 x 5 mL) . The combined organic layers were dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 90/10 to 70/30 v/v) to give the title compound as colourless oil (0.08 g) . Yield: 42%.

¹ H-NMR (CDCl ₃ ) δ 1.29-1.43 (m, 4H), 1.46 (s, 9H), 1.53- 1.78 (m, 5H), 2.24 (m, 2H), 2.34 (s, 3H), 3.51 (m, IH), 3.90 (m, IH, NH), 4.09-4.18 (m, IH), 4.51-4.60 (m, IH), 4.63-4.72 (m, 4H), 5.40 (m, 2H), 6.15 (s, 2H), 6.96 (d, IH, Arom) , 7.06 (d, IH, Arom), 7.32 (t, IH, Arom), 7.58 (t, IH, Arom), 7.85 (s, IH, Arom) , 7.98 (d, IH, Arom) , 8.07 (d, IH, Arom) . ¹³ C-NMR (CDCl ₃ ) δ 14.2, 16.6, 19.6, 21.1, 25.3, 26.8, 28.3, 30.8, 58.4, 60.4, 63.1, 64.8, 74.5, 79.9, 96.2, 100.2, 112.4, 121.8, 122.9, 123.2, 124.5, 124.8, 126.1, 130.0, 132.2, 134.7, 151.1, 154.7, 156.0, 163.0, 164.1, 168.9, 169.7, 189.9.

{ [2- (Acetyloxy) benzoyl] oxyjmethyl 4- [3- (nitrooxy)propoxy] -3- (threonyloxy)benzoate hydrochloride

Dioxane _HC1

HCl

A solution of { [2- (acetyloxy) benzoyl] oxyjmethyl 3-({3- [ tert-butoxycarbonyl) amino] (tetrahydro-2H-pyran-2-yl- oxy) butoxy) -3 (nitrooxy) propoxy] benzoate (105 mg; 0.16 mmol) in dry dioxane/HCl 2.36 M (1.05 mL; 2.41 mmol) was stirred under inert atmosphere for 4 h. The mixture was concentrated under reduced pressure. The crude product was purified by flash chromatography (H ₂ O/CH ₃ CN/HC1 60/40/0.1 v/v/v) to give the title compound as white solid.

Yield: 70%. m.p. : 87.5-88.5 ⁰ C

¹ H-NMR (CDCl ₃ ) δ 1.20 (d, 3H) , 2.07 (m, 2H) , 2.24 (s, 3H) , 3.95 (t, 2H) , 4.18 (m, IH) , 4.25 (m, IH) , 4.44 (t, 2H) , 6.00 (s, 2H) , 6.80 (d, IH, Arom) , 6.959 (d, IH, Arom) , 7.19 (t, IH, Arom) , 7.39 (t, IH Arom, ) , 7.73 (s, IH, Arom) , 7.82 (d, IH, Arom) , 7.95 (d, IH, Arom) , 8.83 (2H, SWiXr) ₁ ¹³ C-NMR (CDCl ₃ ) δ 13.2, 19.5, 21.2, 25.5, 38.5, 64.1, 65.2, 69.1, 79.0, 120.5, 120.9, 122.9, 125.2, 129.3, 131.1, 133.7, 137.4, 150.0, 153.2, 162.0, 162.9, 165.1, 168.7.

Example 9

{ [2- (Acetyloxy) benzoyl] oxy}methyl-3- [2-amino-3- hydroxybutoxy] -4- [2 , 3-bis (nitrooxy) propoxy] benzoate hydrochloride: compound (9) . 2- (Allyloxy) -5-formylphenyl 2- [ (tert- butoxycarbonyl) amino] 3- (tetrahydro-2H-pyran-2-yl- oxy) butanoate

dry

To a solution of 2- [ ( tert-butoxycarbonyl) amino] -3-

(tetrahydro-2H-pyran-2-yl-oxy) butyric acid (800 mg; 2.64 mmol) in dry CH2CI2 (25 mL) , stirred under inert atmosphere,

EDC-HCl (607 mg; 3.17 mmol) and DMAP (32.2 mg; 0.26 mmol) were added. After 1 hour 4- (allyloxy) -3-hydroxybenzaldehyde

(470 mg; 2.64 mmol) was added. The reaction was completed after 14h. The mixture was washed with H ₂ O (20 mL) . The organic layer was dried, filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 90/10 v/v to 70/30) to give the title compound as colourless oil (602 mg) .

Yield: 50%.

¹ H-NMR (CDCl ₃ ) δ 1.40 (d, 2H), 1.42 (d, 2H), 1.48 (s, 9H), 1.66-1.80 (m, 5H), 3.46-3.58 (m, 2H), 3.85-3.92 (m, 2H), 4.55 (m, 2H), 4.69 (m, 2H), 5.29-5.50 (m, 2H, AMX like system + IH), 5.95-5.99 (m, IH, AMX like system), 7.04 (d, IH, Arom) , 7.58 (s, IH, Arom) , 7.75 (d, IH, Arom) , 9.86 (s, IH) . ¹³ C-NMR (CDCl ₃ ) δ 14.2, 16.6, 20.2, 25.3, 28.2, 30.7, 58.5, 63.0, 69.6, 71.3, 74.8, 77.4, 96.4, 100.2, 113.3, 118.5, 123.6, 130.0, 131.7, 140.1, 155.3, 156.0, 169.3, 189.8. MS (CI) m/z 464 (M+l) ⁺ .

2- [2,3-bis (Nitrooxy) propyl] -5-formylphenyl 2- [ (tert- butoxycarbonyl) amino] 3- (tetrahydro-2H-pyran-2-yl- oxy) butanoate

Iodine (315 mg, 1.24 mmol) was added portion wise to a stirred solution of 2- (allyloxy) -5-formylphenyl 2- [ (tert- butoxycarbonyl) amino] -3- (tetrahydro-2H-pyran-2-yl- oxy)butanoate (576 mg, 1.24 mmol) and AgNO ₃ (210 mg, 1.24 mmol) in CH ₃ CN (10 mL) kept at -15 ⁰ C. At the end of the addition, the stirring was continued for Ih. Then AgNO ₃ (527 mg, 3.10 mmol) was added and the mixture was heated at 70 ⁰ C for 16 hours. After cooling the mixture was filtered through Celite ^® . The filtrate was concentrated under reduced pressure, dissolved in water (10 mL) and extracted with EtOAc (3 x 10 mL) . The combined organic layers were washed with brine (10 mL) , dried with MgSO ₄ , filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 75/25 v/v to 60/40 v/v) to give the title compound as colourless oil (327 mg) .

Yield: 47%.

¹ H-NMR (CDCl ₃ ) δ 1.31-1.37 {m, 4H), 1.44 (s, 9H), 1.47- 1.87 (m, 5H), 3.08-3.15 (m, IH), 3.50 (m, IH), 4.31-4.41 (m, 2H), 4.48-4.63 (m, 3H), 4.83-4.87 (m, 2H, AMX like system), 5.30-5.50 (m, IH, AMX like system), 5.59 (m, IH), 7.07 (d, IH, Arom) , 7.64 (s, IH, Arom) , 7.77 (d, IH, Arom) , 9.84 (s, IH) . MS (CI) m/z 560 (M-18) ⁺ .

4- [2,3-bis (Nitrooxy) propyl] -3- ({2- [tert- butoxycarbonyl) amino] -3-hydroxybutoxy) benzoic acid

To a solution of 2- [2, 3-bis (nitrooxy) propyl] -5- formylphenyl 2- [ ( tert-butoxycarbonyl) amino] 3- (tetrahydro- 2H-pyran-2-yl-oxy) butanoate (327 mg, 0.56 mmol) in CH ₃ CN (5 mL) were added a solution of KH ₂ PO ₄ (0.090 g) in H ₂ O (1 mL) and H ₂ O ₂ 30% (69.8 μL, 0.62 mmol) and dropwise a solution of NaClO ₂ 80% (88.6 mg, 0.78 mmol) in H ₂ O (1 mL) . After 2 hours the reaction was completed. Na ₂ SO ₃ was added to destroy the excess of H ₂ O ₂ . After acidification with HCl 6M the mixture was diluted with H ₂ O (15 mL) and extracted twice with CH ₂ Cl ₂ (10 mL) . The organic layer was dried, filtered and concentrated under reduced pressure to give the title compound as colourless oil (330 mg) . Yield: 98%.

¹ H-NMR (CDCl ₃ ) δ 1.25 (s, IH), 1.36 (d, 3H), 1.47 (s, 9H), 4.25-4.33 (m, 2H), 4.45-4.50 (m, IH), 4.55-4.64 (m, 3H), 4.76-4.96 (m, 2H, AMX like system), 5.49-5.57 (m, IH, AMX like system), 5.59-5.64 (m, IH), 6.97 (d, IH, Arom) , 7.27 (d, IH, Arom), 7.891 (s, IH Arom), 8.00 (d, IH, Arom), 12.0 (s, IH) . ¹³ C-NMR (CDCl ₃ ) δ 14.2, 20.2, 24.9, 28.3, 29.7, 48.7, 55.5, 58.8, 65.3, 80.7, 112.5, 123.8, 125.3, 130.1, 139.2, 153.2, 156.5, 169.2, 184.0.

{ [2- (Acetyloxy) benzoyl] oxyjmethyl- 3- ({2- [tert- butoxycarbonyl) amino] 3-hydroxybutoxy) -4- [2,3- bis (nitrooxy) propoxy] benzoate

To a solution of chloromethyl 2- (acetyloxy) benzoate (65.0 mg, 0.28 mmol) in DMF (3 mL) were added 4-[2,3- bis (nitrooxy)propyl] -3- ({2- [ tert-butoxycarbonyl) amino] -3- hydroxybutoxy) benzoic acid (132 mg, 0.28 mmol) and CS2CO ₃

(43.0 mg, 0.14 mmol) . The mixture was stirred for one night, then was poured in H ₂ O (30 inL) and extracted with EtOAc (3 x 5 mL) . The combined organic layers were dried with MgSθ4, filtered and concentrated under reduced pressure. The crude product was purified by flash chromatography (PE/EtOAc 85/15 to 60/40 v/v) to give the title compound as colourless oil (100 mg) .

Yield: 49%.

¹ H-NMR (CDCl ₃ ) δ 1.31 (m, 4H), 1.45 (s, 9H), 2.33 (m, 4H), 4.28 (t, 2H), 4.53 (m, 2H), 4.80 (m, 2H), 4.57 (m, 2H), 6.14 (s, 2H), 6.95 (d, IH, Arom) , 7.10 (d, IH, Arom) , 7.30 (t, IH, Arom), 7.57 (t, IH, Arom), 7.80 (s, IH, Arom), 7.96 (d, IH, Arom), 8.06 (d, IH, Arom) .

{ [2- (Acetyloxy) benzoyl] oxy}methyl-3- [2-amino-3- hydroxybutoxy] -4- [2 , 3-bis (nitrooxy) propoxy] benzoate hydrochloride

Dioxane HCl

HCl

A solution of { [2- (acetyloxy) benzoyl] oxy }methyl-3- ({ 2- [ tert-butoxycarbonyl) amino] -3-hydroxybutoxy) -4- [2, 3- bis (nitrooxy) propoxy] benzoate (110 mg; 0.16 mmol) in dry dioxane/HCl 2.36 M (1.00 mL, 2.32 mmol), was stirred under inert atmosphere for 4 hours. The mixture was concentrated under reduced pressure. The crude product was purified by flash chromatography (H ₂ O/CH ₃ CN/HC1 70/30/0.1 v/v to 60/40/0.1) to give the title compound as white solid (90 mg) .

Yield: 90%. m.p. : 57.0-58.5 ⁰ C

¹ H-NMR (CDCl ₃ ) δ 1.43 (3H, m) , 2.31 (3H, s) , 4.18-4.45

(3H, m) , 4.65-4.85 (3H, m) , 5.70 (IH, m) , 6.09 (2H, s) , 6.92 (IH, d, Arom) , 7.08 (IH, d, Arom) , 7.27 (IH, t, Arom) , 7.55

(IH, t, Arom), 7.79 (IH, s, Arom), 7.91 (IH, d, Arom), 8.04

(IH, d, Arom), 8.58 (svvbr, 2H) .

Hydrolysis experiments

Hydrolysis in acidic medium (pH 1) and in phosphate buffer (pH 7.4)

A solution of each compound (10 mM) in acetonitrile was added to a HCl 0. IM or to a phosphate buffer 50 mM pH = 7.4, containing, when necessary, 10-20% of acetonitrile as cosolvent. The final concentration of the compound was 250 μM. Resulting solution was kept at 37 ± 0.5 ⁰ C and at appropriate time intervals a 20 μL aliquote of reaction solution was analysed by RP-HPLC.

Hydrolysis in human serum. A solution of each compound (10 mM) in acetonitrile was added to human serum (from human male AB plasma, Sigma) preheated at 37 ⁰ C; the final concentration of the compound was 250 μM.

The resulting solutions were incubated at 37 ± 0.5 ⁰ C and, at appropriate time intervals, 300 μL of reaction mixture was withdrawn and added to 450 μL of acetonitrile containing 0.1% trifluoroacetic acid in order to deproteinize the serum. Sample was sonicated, vortexed and then centrifuged for 10' at 2150 g. The clear supernatant was filtered by 0.45 μm PTFE filters (Alltech) and analysed by RP-HPLC.

The reverse-phase HPLC procedure allowed separation and quantification of remaining compound and of products of hydrolysis (aspirin, salycilic acid, salicylate and nitrooxy-substituted carboxylic acid) .

Quantitation was done by comparison of peak areas with standards chromatographed under the same conditions. Analyses were carried out with a HP 1100 chromatograph system (Agilent Technologies, Palo Alto, CA, USA) equipped with a quaternary pump (model G1311A) , a membrane degasser

(G1379A), a diode-array detector (DAD) (model G1315B) integrated in the HPIlOO system. Data analysis was done using a HP ChemStation system (Agilent Technologies) . The analytical column was a Nucleosil 100-5C18 Nautilus (250 x 4.6 mm, 5 μm particle size) (Macherey-Nagel) .

The samples were analysed using a gradient method employing a mobile phase consisting of acetonitrile/water with 0.1% trifluoroacetic acid 40/60 over the first 2 min, grading to 60/40 to 11 min, keeping 60/40 until 16 min and then back to 40/60 to 20 min. The flow-rate was 1.2 mL/min. The injection volume was 20 μL (Rheodyne, Cotati, CA) . The column effluent was monitored at 240 nm (for salicylic acid) and at 226 nm (for all the other products) and referenced against a 360 nm wavelength.

The hydrolysis followed first-order kinetics. The observed pseudo-first-order rate constants (kobs) were calculated from the slopes of linear plots of the natural logaritms of percent remaining products against time and the corresponding half-lives (ti _/ 2) were obtained from t _1/2 =0 . 693 / k _obs Table 1 reports: the stability in human serum (half-life, percentage of maximal amounts of aspirin (ASA) released and the time of the maximal release (interval in min) ) ; the stability in buffered solutions (percentage of unchanged compound after 3 hours)

The data show that the compounds of the present invention are stable in acid media and release aspirin when incubated in human serum.

Table 1: Stability in human serum (half-life, percentage of maximal amounts of aspirin (ASA) released and range of values) ; stability in buffered solutions (percentage of unchanged compound after 3 hours)

Inhibition of platelet aggregation in vitro

The ability of aspirin nitroderivatives to inhibit platelet aggregation was evaluated in vitro in human platelets . Venous blood samples were obtained from healthy volunteers who had not taken any drug for at least two weeks. Platelet rich plasma (PRP) was prepared by centrifugation of citrated blood at 200 g for 20 minutes. Aliquots (500 μL) of PRP were added into aggregometer (Chrono-log model 4902D) cuvettes and aggregation is recorded as increased light transmission under continuous stirring (1000 rpm) at 37 ⁰ C for 10 minutes after addition of the stimulus (collagen) . Collagen (0.8-1.5 μg/mL) is used as platelet activator in PRP. The inhibitory activity of the compounds is tested by addition of drug to PRP 10 min before addition of the stimulus. Drug vehicle (0.5 % DMSO) added to PRP did not affect platelet function in control samples.

The antiaggregatory activity of tested compounds is evaluated as percentage of inhibition of platelet aggregation compared to control samples. For most active compounds IC _5O values could be calculated by non-linear regression analysis, otherwise % inhibition at maximal concentration tested (300 μM) is reported.

The data in Table 2 show that the nitroderivatives inhibited platelet aggregation.

Table 2: Antiaggregatory activities

Vasodilating activity

Thoracic aortas were isolated from male Wistar rats weighing 180 - 200 g. The endothelium was removed and the vessels were helically cut: three strips were obtained from each aorta. The tissues were mounted under 1.0 g tension in organ baths containing 30 ml of Krebs-bicarbonate buffer with the following composition (mM) : NaCl 111.2, KCl 5.0, CaCl ₂ 2.5, MgSO ₄ 1.2, KH ₂ PO ₄ 1.0, NaHCO ₃ 12.0, glucose 11.1, maintained at 37°C and gassed with 95% O ₂ - 5% CO ₂ (pH = 7.4) . The aortic strips were allowed to equilibrate for 120 min and then contracted with 1 μM L-phenylephrine . When the response to the agonist reached a plateau, cumulative concentrations of the vasodilating agent were added. Results in Table 3 are expressed as EC ₅₀ ± SE (μM) .

The compounds of the invention relaxed precontracted rat aorta strips in a concentration dependent manner.

Vasodilating potencies expressed as EC 50 + SE (μM), calculated by a linear regression analysis, are reported in Table 3. When the experiments were repeated in the presence of 1 μM ODQ ( IH-[1 , 2 , 4]oxadiazolo[4 , 3-a]quinoxalin-l-one) , which is an inhibitor of the soluble guanylate cyclase (sGC) , a decrease in the vasodilator potencies was observed.

Table 3: Vasodilator activity

Water solubility

The solubility of the compounds in water was determined at 25 ±1 ⁰ C adding excess amounts of the compounds to water in test tubes; the mixtures were sonicated for 10 min and then kept under magnetic stirring for 30 min. This time was choosen in order to minimise hydrolysis during the test. After filtration, an aliquot of the filtrate was diluted with an appropriate amount of water and analysed by HPLC. Table 4: Water solubility