Field of the Invention

The present invention relates to monosaccharide derivatives as anti-inflammatory agents. The compounds disclosed herein can be useful for inhibition and prevention of inflammation and associated pathologies including inflammatory and autoimmune diseases such as bronchial asthma, rheumatoid arthritis, type I diabetes, multiple sclerosis, allograft rejection, psoriasis, inflammatory bowel disease, ulcerative colitis, acne, atherosclerosis, cancer, pruritis or allergic rhinitis. Pharmacological compositions containing compounds disclosed herein and the methods of treating bronchial asthma, chronic obstructive pulmonary disease, rheumatoid arthritis, multiple sclerosis, type I diabetes, psoriasis, allograft rejection, inflammatory bowel disease, ulcerative colitis, acne, atherosclerosis, cancer, pruritis, allergic rhinitis and other inflammatory and/or autoimmune disorders, using the compounds are also provided. Background of the Invention

Inflammation is a key defence mechanism of the body that is activated as a result of tissue injury. The inflammatory process is self-containing, however, under certain pathophysiological conditions the inflammatory process tends to perpetuate itself, giving rise to chronic inflammatory diseases like bronchial asthma, rheumatoid arthritis etc. Although the exact cellular and molecular bases of most chronic inflammatory disease remain unclear, it has become apparent that several inflammatory cells act in concert towards initiation and perpertuation of an inflammatory response by releasing a wide range of chemokine, cytokine, proteolytic enzymes and other bioactive molecules. Mast cells primed by lymphocytes interact with environmental allergens and release mediators like histamine, prostaglandin, leukotrienes etc (Clin. Exp. Allergy 32, 1682, 2002) to initiate an early inflammatory response. This is followed by a delayed inflammatory response due to release of cytokines (IL-4, IL-5, IL-6, IL-8, IL-13, GM-CSF and TNFalpha), chemokines and proteolytic enzymes (chymase, tryptase) (Chest 112, 523, 1997; Lancet 350, 59, 1997) that not only bring about tissue damage, but attract other inflammatory cells and initiate tissue fibrosis, and the cycle continues. Eosinophils

infiltrate inflamed tissue following allergen - mast cell interaction in bronchial asthma and allergic rhinitis. Evidence is emerging that mast cells also interact with bacterial endotoxins leading to generation of cytokines like TNFalpha, that encourage neutrophil influx into the site of inflammation (Br. J. Pharmacol.123, 31, 1998; Br. J. Pharmacol. 128, 700, 1999; Br. J. Pharmacol. 136, 111 , 2002; J. Clin. Invest. 109, 1351 , 2002).

Involvement of mast cells in the inflammatory response of chronic obstructive pulmonary disease (New Eng. J. Med. 347, 1040, 2002; Thorax 57, 649, 2002), inflammatory bowel disease (Gut. 45 Suppl. 116, 1999) as well as in rheumatoid arthritis (Science 297, 1626, 2002), pathologies with prominent neutrophilic inflammation, has been proposed. U.S. Patent 6,329,344Bl discloses several monosaccharide derivatives said to be useful as cell adhesion inhibitors. It generally relates to substituted pentose and hexose monosaccharide derivatives, which are said to exhibit cell adhesion inhibitory and anti- ^Λ inflammatory activities. U.S. Patent 6,590,085Bl discloses several monosaccharide derivatives described as inhibitors of cell adhesion and cell adhesion mediated pathologies, including inflammatory and autoimmune diseases. U.S. Patent Application US 2002/0173632 Al discloses furanose and amino furanose compounds reportedly useful for rheumatoid, arthritis, immunomodulatory diseases inflammatory and proliferative diseases. U.S. Patent 5,298,494 discloses derivatives of monosaccharides, which are said to exhibit antiproliferative and/or anti-inflammatory activity and are useful for treating mammals having inflammatory disorders and/or autoimmune disorders. U.S Patent

4,996,195 discloses derivatives of α,D-glucofuranose and α,D-allofuranose described as useful for treating animals and mammals with inflammatory and/or autoimmune disorders.

WO 93/13117 and U.S. Patent 5,360,792 discloses 5- or 6-deoxy hexose monosaccharides having a saturated nitrogen containing heterocycle described as useful as anti-proliferative and anti-inflammatory compounds. WO 94/28910 discloses 5,6- dideoxy-5-amino derivatives of idose and 6-deoxy-6-amino derivatives of glucose, which reportedly exhibit immunomodulatory, anti-inflammatory and anti-proliferative activity. WO 94/11381 discloses derivatives of pentose monosaccharides described as useful as anti-proliferative. and anti-inflammatory compounds. U.S. Patent 5,010,058 discloses 3,5,6-disubstituted derivatives of l,2-0-isopropylidene-α,0-glucofuranoside described as useful for treating inflammatory and autoimmune disorders. U.S. Patent 4,849,512

discloses 3-acylamino-3-deoxyallose derivatives. U.S. Patent 5,367,062 discloses disubstituted and deoxy disubstituted derivatives of α-D-lyxofuranosides reportedly having anti-inflammatory and antiproliferative activity. U.S. Patent 5,360,794 discloses disubstituted derivatives of α-D-mannofuranoside reportedly having anti-inflammatory and anti proliferative activity. WO 03/029263 discloses 3-deoxy-3-amide derivatives of carbohydrates described as useful as inducers of erythroid cell differentiation. FR 2735130 discloses regiospecific synthesis of new carbamic polyesters.

Summary of the Invention

Monosaccharide derivatives which can be used for the inhibition and prevention of inflammation and associated pathologies, including inflammatory and autoimmune diseases such as bronchial asthma, rheumatoid arthritis, type I diabetes, multiple sclerosis, allograft rejection or psoriasis are provided herein. Pharmaceutically acceptable salts, pharmaceutically acceptable solvates, enantiomers, diastereomers or N-oxides of these compounds having the same type of activity are also provided. Pharmaceutical compositions containing the compounds, and which may also contain pharmaceutically acceptable carriers or diluents, which may be used for the treatment of inflammatory and autoimmune diseases such as bronchial asthma, rheumatoid arthritis, type I diabetes, multiple sclerosis, allograft rejection, psoriasis, inflammatory bowel disease, ulcerative colitis, acne, atherosclerosis, cancer, pruritis and allergic rhinitis are provided herein. Other aspects will be set forth in accompanying description which follows and in part will be apparent from the description or may be learnt by the practice of the invention.

In accordance with one aspect, there are provided compounds having the structure of Formula I.

Formula I Ri and R ₂ can together form a five-membered acetal, wherein the carbon atom joining the oxygens can be substituted with R _L and R _m [wherein R _L and R _m are independently selected

from hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, or aralkyl; or RL and R _m can together join to form a 3-8 membered ring, wherein the ring may optionally contain one or more heteroatoms selected from O, N or S, and the ring may be optionally substituted with one or more of alkyl, alkenyl, alkynyl, amino, substituted amino, cycloalkyl, oxo, hydroxy, carboxy, -COQR ₆ (wherein Q is O or NH and R ₆ is selected from alkyl, alkenyl, alkynyl, aryl, aralkyl, and cycloalkyl), alkoxy, aryloxy, halogen (F,C1, Br, I), aryl, aralkyl, heteroaryl, heterocyclyl, heteroarylalkyl, or heterocyclylalkyl; or RL and R _m can together join to form an oxo group].

R ₃ can be A) -(CH ₂ ) _n G wherein n is an integer from 0-5 and G is selected from 1) OR _e {wherein Rj is selected from a) acyl (with the proviso that n cannot be 0), and b) -C(=O)NR _f R _q [wherein R _f and R _q can be independently selected from hydrogen, hydroxy (with the restriction that both R _f and R _q cannot both be hydroxy), alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl, heteroaryl, heterocyclyl, and S(O) ₂ R ₇ (wherein R ₇ is selected from alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl, heteroaryl, heterocyclyl, heterocyclylalkyl, heteroarylalkyl, and optionally substituted amino)]; and Rf and R _q may also together join to form a heterocyclyl ring; also, when n is zero, then R _f and R _q cannot be hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl and R _f and R _q together cannot join to form a heterocyclyl ring};

2) -NR _j C(=O)OR _s (wherein R _j is selected from hydrogen, lower (Ci-C ₆ ) alkyl, lower (C ₂ -C ₆ ) alkenyl, lower (C ₂ -C ₆ ) alkynyl, lower (C ₃ -C ₆ ) cycloalkyl, aryl, heteroaryl (with the proviso that the heteroaryl ring is not linked through a heteroatom), aralkyl (Ci- C ₄ ), heteroarylalkyl (Ci-C ₄ ), and heterocyclylalkyl (Ci-C ₄ ), and R _s is selected from alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl, heterocyclylalkyl, or heteroarylalkyl);

3) NRjYR _u (wherein Rj is the same as defined above and Y is -C(=O), -C(=S) or SO ₂ and R _u is selected from alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl, heteroaryl, heterocyclyl, heteroarylalkyl, and heterocyclylalkyl; and when n is 0 then Y cannot be - C(=O));

4) -NRjC(=T)NR _t Rχ (wherein R _t is OH or R _x and T is O, S, -N(CN), -N(NO ₂ ), - CH(NO ₂ ), R _j is the same as defined above and R _x is selected from hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl, heteroaryl, heterocyclyl, heteroarylalkyl, heterocyclylalkyl, and S(O) ₂ R ₇ wherein R ₇ is the same as defined above); 5) heterocyclyl;

6) heteroaryl; and

7) -(C=O)NR ₃ R _b (wherein R ₃ and R _b are independently selected from hydrogen, and Ru wherein R ₄₁ is same as defined earlier, also, R ₃ and Rb together with the nitrogen atom carrying them can be the N-terminus of an amino acid or di-tetrapeptide or R _a and R _b may together join to form a heterocyclyl ring).

R ₃ can also be

B) -NR _j R _n , (wherein R _j is the same as defined above and R _m is selected from alkyl, cycloalkyl, aryl, aralkyl, heteroaryl, heterocyclyl, heteroarylalkyl, and heterocyclylalkyl);

C) -0(CH ₂ ) _w Gi [wherein w is an integer from 1-5 (and Gi is selected from OR _e (wherein Re is the same as defined above), -NR _j C(=O)OR _s (wherein R _j and R _s are the same as defined above), -NR _j C(==T)NR _t R _x (wherein R _j , T, R ₁ and R _x are the same as defined above), -NRjYR ₁₁ (wherein Y, R ₁₁ and R _j are the same as defined above), heterocyclyl, and heteroaryl)];

D) -NR _j (CH ₂ ) _w Gi (wherein w, R _j and Gi are the same as defined above); E) -O(CH ₂ ) _W G ₂ [wherein w is the same as defined above (and G ₂ is selected from -C(=0)NR ₃ R _b (wherein R ₃ and Rb are the same as defined above), and -C(=O)OR _k (wherein R _k is H or R^ and R ₆ is the same as defined above); or

F) -NRj(CH ₂ ) _w G ₂ (wherein w is as defined above, Rj and G ₂ are the same as defined above))]. Also, when R ₃ is ORe then R ₂ and R _e may together join to form a five membered acetal wherein the carbon linking the two oxygens is substituted with R _L and R _m (wherein R _L and R _m are the same as defined earlier) (and Ri is independently selected from

a) -(CH ₂ ) _t Gi (wherein t is an integer from 2-4 and Gi are the same as defined above and also when Gi is heterocyclylalkyl group then the group cannot be 4-(l- pyrrolidinyl) butyl), b) -(CH ₂ ) _W G ₂ (wherein w and G ₂ are the same as defined above), c) aryl, d) aralkyl (with the proviso that aralkyl cannot be phenylpropyl), e) heteroaryl, and f) heterocyclyl (wherein the heteroaryl and heterocyclyl rings are not linked through a heteroatom), and cycloalkyl (with the proviso that cycloalkyl cannot be cycloocryl).

R ₄ and R ₅ can independently be selected from hydrogen, lower alkyl, lower (C ₂ - Cό) alkenyl, lower (C ₂ -C _O ) alkynyl, lower (C ₃ -C ₈ ) cycloalkyl, aryl, acyl, heterocyclyl, heteroaryl, lower (C ₁ -C ₄ ) heterocyclylalkyl, and lower (Ci -C ₄ ) heteroarylalkyl; or R ₄ and Rs may together form a five-membered acetal wherein the carbon linking the two oxygens is substituted with R _L and R _m (wherein R _L and R _m are the same as defined earlier) with the proviso that when R ₃ is OR _e then the acetal must be isopropylidene acetal.

The following definitions apply to terms as used herein

The term "alkyl" unless otherwise specified, refers to a monoradical branched or unbranched saturated hydrocarbon chain having from 1 to 20 carbon atoms. This term is exemplified by groups such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, t- butyl, n-hexyl, n-decyl, tetradecyl, and the like.

Alkyl may further be substituted with one or more substituents selected from alkenyl, alkynyl, alkoxy, cycloalkyl, cycloalkenyl, acyl, acylamino, acyloxy, alkoxycarbonylamino, azido, cyano, halogen, hydroxy, oxo, thiocarbonyl, carboxy, - COOR _ό (wherein R ₆ is the same as defined earlier), arylthio, thiol, alkylthio, aryloxy, aminosulfonyl, -NR _j C(=O)R _u , -NR ₁ R _x , -C(=O)NR _a R _b , -NHC(=O)NR _x R _t ,, - N(OH)C(=O)NR _x R _t , -C(=O)heteroaryl, C(=O)heterocyclyl, -OC(=O)NR _x R _t (wherein R _j , R ₃ , Rb, Ru, R _x and R _t are the same as defined earlier), nitro, -S(O) _m R ₇ (wherein m is an integer from 0-2 and R ₇ is the same as defined earlier). Unless otherwise constrained by

the definition, all substituents may be further substituted by 1-3 substituents chosen from alkyl, carboxy, -COOR ₆ (wherein R ₆ is the same as defined earlier), -NR _t R _x , - C(=0)NR _a R _b , -0C(=0)NR _x R,,. -N(0H)C(=0)NR _x Rt, -NHC(=0)NR _x R, (wherein R ₃ , R _b R _x and R _t are the same as defined earlier), hydroxy, alkoxy, halogen, CF ₃ , cyano, and - S(O) ₀₁ R ₇ (where R ₇ and m are the same as defined earlier); or an alkyl group as defined above may also be interrupted by 1-5 atoms of groups independently chosen from oxygen, sulfur and -NR _f , where R _f is chosen from hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, aryl, acyl, aralkyl,-C(=0)0R _{6 (} wherein R ₆ is the same as defined earlier), S(O) ₂ R ₇ (where R ₇ is same as defined earlier), -C(=0)NR _a Rb (wherein R ₃ , Rb, R _x and R _t are as defined earlier).

The term "alkenyl," unless otherwise specified, refers to a monoradical of a branched or unbranched unsaturated hydrocarbon group preferably having from 2 to 20 carbon atoms with cis or trans geometry. In the event that alkenyl is attached to the heteroatom, the double bond cannot be alpha to the heteroatom. Alkenyl groups may further be substituted with one or more substituents selected from alkyl, alkynyl, alkoxy, cycloalkyl, cycloalkenyl, acyl, acylamino, acyloxy, -NRjC(=O)R _u , -NR _x R ₁ , -C(=O)NR _a Rb, -NHC(=0)NR _x R _t , -OC(O)NR _x R ₁ (wherein Rj, R ₃ , R ₁₁ ,R _b , R _x and R _t are the same as defined earlier), alkoxycarbonylamino, azido, cyano, halogen, hydroxy, oxo, thiocarbonyl, carboxy, -COOR ₆ (wherein R ₆ is the same as defined earlier), arylthio, thiol, alkylthio, aryl, aralkyl, aryloxy, heterocyclyl, heteroaryl, heterocyclyl alkyl, heteroaryl alkyl, aminosulfonyl, alkoxyamino, nitro, and S(O) _1n R ₇ (wherein R ₇ and m are the same as defined earlier). Unless otherwise constrained by the definition, all substituents may optionally be further substituted by 1-3 substituents chosen from alkyl, carboxy, -COOR ₆ (wherein R ₆ is the same as defined earlier), hydroxy, alkoxy, halogen, - CF ₃ , cyano, -NR _x R ₁ , -C(=0)NR _a R _b , -0C(=0)NR _x R _t (wherein R _x R _a , R _b and R _y are the same as defined earlier) and -S(O) _m R ₇ , (where R ₇ and m are the same as defined earlier).

The term "alkynyl," unless otherwise specified, refers to a monoradical of an unsaturated hydrocarbon, preferably having from 2 to 20 carbon atoms. In the event that alkynyl is attached to the heteroatom, the triple bond cannot be alpha to the heteroatom. Alkynyl groups may further be substituted with one or more substituents selected from alkyl, alkenyl, alkoxy, cycloalkyl, cycloalkenyl, acyl, acylamino, acyloxy,

alkoxycarbonylamino, azido, cyano, halogen, hydroxy, oxo, thiocarbonyl, carboxy, - COOR ₆ (wherein R ₆ is the same as defined earlier), arylthio, thiol, alkylthio, aryl, aralkyl, aryloxy, aminosulfonyl, nitro, heterocyclyl, heteroaryl, heterocyclyl alkyl, heteroarylalkyl, -NR _j C(O)Ru , -NR ₁ R _x , ,-C(=O)NRaR _b , -N(OH)C(=O)NR _x R _t , -NHC(O)NR _x R,,, -O- C(=0)NR _x R _t (wherein R _j , R _a , Rb, R _u , R _x and R _t are the same as defined earlier). Unless otherwise constrained by the definition, all substituents may optionally be further substituted by 1 -3 substituents chosen from alkyl, carboxy, -COORβ (wherein R _O is the same as defined earlier), hydroxy, alkoxy, halogen, CF3, NR _t R _x , -C(=O)NR _a Rb, - N(0H)C(=0)NR _x R _t , -NHC(=O)NR _x R _t (wherein R _a , R _b , R _x and R _t are the same as defined earlier), cyano, and -S(O) _m R ₇ (where R ₇ and m are the same as defined earlier).

The term "cycloalkyl," refers to cyclic alkyl groups of from 3 to 20 carbon atoms having a single cyclic ring or multiple condensed rings, which may optionally contain one or more olefinic bonds, unless otherwise constrained by the definition. Such cycloalkyl groups include, by way of example, single ring structures such as cyclopropyl, cyclobutyl, cyclooctyl, cyclopentenyl, and the like, or multiple ring structures such as adamantanyl, and bicyclo [2.2.1] heptane, or cyclic alkyl groups to which is fused an aryl group, for example indane, and the like. Cycloalkyl groups may further be substituted with one or more substituents selected from alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, cycloalkenyl, acyl, acylamino, acyloxy, alkoxycarbonylamino, azido, cyano, halogen, hydroxy, oxo, thiocarbonyl, carboxy, -COORe (wherein R ₆ is the same as defined earlier), arylthio, thiol, alkylthio, aryl, aralkyl, aryloxy, aminosulfonyl, -NRjC(O)R ₁₁ , -NR _t R _x , -C(O)NR ₃ Rb, - N(OH)C(O)NR _x R,, -NHC(O)NR _x R, _, , -OC(O)NR _x R, (wherein R _j , R _a , R _b , R _u , R _x and R, are the same as defined earlier), nitro, heterocyclyl, heteroaryl, heterocyclylalkyl, heteroarylalkyl, and S(O) _1n -R ₇ (wherein R ₇ and m are the same as defined earlier). Unless otherwise constrained by the definition, all substituents may optionally be further substituted by 1 -3 substituents chosen from alkyl, carboxy, -COORβ (wherein R ₆ is the same as defined earlier), hydroxy, alkoxy, halogen, CF3, -NR _t R _x , -C(O)NR _a Rb , - N(OH)C(O)NR _x R,, -NHC(O)NR _x R,,, -C(O)NR _x R _y , -NHC(O)NR _x R, , -OC(O)NR _x Ry (wherein R ₃ , Rb, R _x , R _t and R _y are the same as defined earlier), cyano, and -S(0) _m R7, (where R ₇ and m are the same as defined earlier).

The term "alkoxy" denotes the group O-alkyl wherein alkyl is the same as defined above.

The term "aralkyl" refers to alkyl-aryl linked through alkyl (wherein alkyl is the same as defined above) portion and the alkyi portion contains carbon atoms from 1-6 and aryl is as defined below. Examples of aralkyl groups include benzyl and the like.

The term "aryl" herein refers to a carbocyclic aromatic group, for example phenyl, biphenyl or naphthyl ring and the like optionally substituted with 1 to 3 substituents selected from -(CH ₂ ) _w C(=O)R _g (wherein w is an integer from 1-4 and R _g is hydroxy), - OR _Z (wherein R _z is hydrogen, alkyl, aralkyl, heteroaryl alkyl), -NR _x R _t , -NHOR ₂ or - NHOH, halogen (F, Cl, Br, I), hydroxy, alkyl, alkenyl, alkynyl, cycloalkyl, alkoxy, acyl, aryloxy, cyano, nitro, -NRjC(=O)R _u , -NR _x Rt, -N(0H)C(=0)NR _x R,, - NHC(=O)NR _X R, , -(SO ₂ ) _m R7 (wherein R ₇ , R _x , R ₁ , R ₁₁ , R ₂ and R _t and m are the same as defined earlier), carboxy, -COOR ₆ (wherein R ₆ is the same as defined earlier), heterocyclyl, heteroaryl, heterocyclylalkyl, heteroarylalkyl. The aryl group may optionally be fused with cycloalkyl group wherein the cycloalkyl group may optionally contain heteroatoms selected from the group consisting of O, N, S.

The term "aryloxy" denotes the group O-aryl wherein aryl is the same as defined above.

The term "carboxy" as defined herein refers to -C(=0)0H. The term "heteroaryl," unless otherwise specified, refers to an aromatic ring structure containing 5 or 6 atoms, or a bicyclic aromatic group having 8 to 10 atoms, with one or more heteroatom(s) independently selected from N, O and S optionally substituted with 1 to 3 substituent(s) selected from halogen (F, Cl, Br, I), hydroxy, alkyl, alkenyl, alkynyl, cycloalkyl, acyl, carboxy, -COOR ₆ (wherein R ₆ is the same as defined earlier), aryl, alkoxy, aralkyl, cyano, nitro, -NR _x R _t , -(CH ₂ ) _w C(=O)R _g (wherein w is an integer from 1-4 and R _g is hydroxy, OR ₂ , NR _x R,, -NHOR ₂ or -NHOH), -C(=0)NR _a R _b , - N(0H)C(=0)NR _x R _t , and -NHC(O)NR _x R, , -SO ₂ R ₇ , and -0C(=0)NR _x R _t (wherein R ₇ , R _{2 ;} R,, R _x , R _a and R _b are the same as defined earlier). Unless otherwise constrained by the definition, the substituents are attached to the ring atom, be it carbon or heteroatom. Examples of heteroaryl groups can include pyridinyl, pyridazinyl, pyrimidinyl, pyrrolyl,

oxazolyl, thiazolyl, thienyl, isoxazolyl, triazinyl, furanyl, benzofuranyl, indolyl, benzothiazolyl, benzoxazolyl, and the like.

The term 'heterocyclyl," unless otherwise specified, refers to a non-aromatic monocyclic or bicyclic cycloalkyl group having 5 to 10 atoms in which 1 to 3 carbon atoms in the ring are replaced by heteroatoms selected from O, S or N, and are optionally benzofused or fused heteroaryl of 5-6 ring members and/or are optionally substituted wherein the substituents are selected from halogen (F, Cl, Br, I), hydroxy, alkyl, alkenyl, alkynyl, cycloalkyl, acyl, aryl, alkoxy, alkaryl, cyano, nitro, oxo, carboxy, -COORs (wherein R ₆ is the same as defined earlier), -C(=O)NR _a Rb, SO ₂ R ₇ , -0C(=0)NR _x R _t , - N(OH)C(O)NR _x R,, -NHC(=0)NR _x R _t , and -NR _x R, (wherein R _a , R _b , R ₇ , R _x and R, are the same as defined earlier). Unless otherwise constrained by the definition, the substituents are attached to the ring atom, be it carbon or heteroatom. Also unless otherwise constrained by the definition, the heterocyclyl ring may optionally contain one or more olefimc bond(s). Examples of heterocyclyl groups can include tetrahydrofuranyl, dihydrofuranyl, dihydropyridinyl, dihydrobenzofuryl, azabicyclohexyl, dihydroindolyl, piperidinyl or piperazinyl.

"Heteroarylalkyl" refers to alkyl-heteroaryl group linked through alkyl portion, wherein the alkyl and heteroaryl are the same as defined earlier.

"Heterocyclylalkyl" refers to alkyl-heterocyclyl group linked through alkyl portion, wherein the alkyl and heterocyclyl are the same as defined earlier.

"Acyl" refers to -C(=0)R" wherein R" is selected from the group alkyl, cycloalkyl, aryl, aralkyl, heteroaryl, heterocyclyl, heteroarylalkyl or heterocyclylalkyl.

"Substituted amino," unless otherwise specified, refers to -N(R _k ) ₂ wherein each R _k is independently selected from hydrogen (provided that both R _k groups are not hydrogen, defined as "amino"), alkyl, alkenyl, alkynyl, aralkyl, cycloalkyl, aryl, heteroaryl, heterocyclyl, heterocyclylalkyl, heteroarylalkyl, acyl, S(O) _m R ₇ (wherein m and R ₇ is the same as defined above), -C(=R _v )NR _x R _t or -NHC(=R _v )NR _t R _x (wherein R _v is O or S and R _t and R _x are the same as defined earlier). Unless otherwise constrained by the definition, all substituents may optionally be further substituted by 1-3 substituents chosen from alkyl, aralkyl, cycloalkyl, aryl, heteroaryl, heterocyclyl, carboxy, -COOR ₆ , (wherein R ₆ is the same as defined earlier), hydroxy, alkoxy, halogen, CF ₃ , cyano, -C(=R _v )NR _x R _t , -

0(C=O)NR _x R _t (wherein R _x , R _t and R _v are the same as defined earlier), -OC(=R _v )NR _x R _ti , and -S(O) ₁₁₁ R ₇ , (where R ₇ is the same as defined above and m is O, 1 or 2).

The term "leaving group" generally refers to groups that exhibit the properties of being labile under the defined synthetic conditions and also, of being easily separated from synthetic products under defined conditions. Examples of such leaving groups include, but are not limited to, halogen (F, Cl, Br, I), triflates, tosylate, mesylates, alkoxy, thioalkoxy, hydroxy radicals and the like.

The term "activated derivative of a carboxylic acid," can include, for example, protected amino acids, aliphatic acids or aromatic acids converted to their corresponding acyl halides (e.g., acid fluoride, acid chloride and acid bromide), corresponding activated esters (e.g., nitro phenyl ester, the ester of 1-hydroxybenzotriazole or the ester of hydroxysuccinimide, HOSu) or mixed anhydrides, for example, anhydride with ethyl chloroformate and other derivatives within the skill of the art.

The term "protecting groups" is used herein to refer to moieties which have the property of preventing specific chemical reaction at a site on the molecule undergoing chemical modification intended to be left unaffected by the particular chemical modification. Also the term protecting group, unless otherwise specified, may be used with groups such as hydroxy, amino and carboxy. Examples of such groups are found in T.W. Greene and P.G.M. Wuts, "Protective Groups in Organic Synthesis", 2 ^nd Ed., John Wiley and Sons, New York, N. Y. The species of the carboxylic protecting groups, amino protecting groups or hydroxy protecting group employed are not critical, so long as the derivatised moieties/moiety is/are stable to conditions of subsequent reactions and can be removed without disrupting the remainder of the molecule.

"Amino acid" refers to both natural and unnatural amino acids. The term "natural amino acid," as used hereind, is intended to represent the twenty two naturally-occurring amino acids glycine, alanine, valine, leucine, isoleucine, serine, methionine, threonine, phenylalanine, tyrosine, trytophan, cysteine, proline, proline, histidine, aspartic acid, asparagines, glutamic acid, glutamine, γ-carboxyglutamic acid, arginine, ornithine and lysine in their L form. The term "unnatural amino acid," as used herein, is intended to represent the 'D' form of the twenty two naturally-occurring amino acids described above. It is further understood that the term unnatural amino acid includes homologues of the

natural amino acids, and synthetically modified form of the natural amino acids commonly utilized by those in the peptide chemistry arts when preparing synthetic analogues of naturally occurring peptides, including D and L forms. The synthetically modified forms include amino acids having alkylene chains shortened or lengthened by up to two carbon atoms, amino acids comprising optionally substituted aryl groups, and amino acids comprised halogenated groups preferably halogenated alkyl and aryl groups. The term "unnatural amino acids" as used herein is also intended to represent beta amino acids.

The term "peptide" refers to a molecule comprising amino acids linked through amide linkages. Dipeptide comprises of 2 amino acids, tripeptide refers to a peptide having 3 amino acids and tetrapeptide refers to one having four amino acids, wherein the term amino acid is as defined earlier. "LDVP" refers to a tetrapeptide leucyl-aspartyl-valyl- prolyl. "DVP" refers to a tripeptide aspartyl-valyl-prolyl. "VP" refers to a dipeptide valyl-prolyl.

Compounds disclosed herein contain one or more asymmetric carbon atoms and thus can exist as racemates and racemic mixtures, single enantiomers, diastereomieric mixtures and individual diastereomers. All such isomeric forms of these compounds are expressly included herein. Each stereogenic carbon may be of the R or S configuration. Although the specific compounds exemplified in this application may be depicted in a particular stereochemical configuration, compounds having either the opposite stereochemistry at any given chiral center or mixtures thereof are envisioned. Although amino acids and amino acid side chains may be depicted in a particular configuration, both natural and unnatural forms are envisioned.

Detailed Description of the Invention Compounds disclosed herein may be prepared by techniques well known in the art and familiar to a practitioner of ordinary skill in art. In addition, compounds disclosed herein may be prepared by the processes described herein, these processes are not the only means by which the compounds described may be synthesised. Further, synthetic steps described herein may be performed in an alternate sequence or order to give the desired compounds.

Scheme I

Formula Il Formula III Formula IV

Vl

Formula V J Q Formula VII

Compounds of Formula VII can be prepared by Scheme I. Thus, a compound of Formula II (wherein R ₁ , R ₂ , R ₄ and R ₅ are the same as defined earlier) can be oxidized to form a compound of Formula III, which can be reacted with hydroxylamine hydrochloride 15 to form a compound of Formula IV, which can undergo reduction to form a compound of Formula V, which can be reacted with a compound of Formula VI (wherein X is O or S and R _x the same as defined earlier) to furnish a compound of Formula VII.

The oxidation of a compound of Formula II to form a compound of Formula III can be carried out under various conditions. For example, one may use Swern's oxidation 0 utilizing dimethyl sulphoxide and acetic anhydride or oxalyl chloride, optionally in either dimethyl sulphoxide or dichloromethane as solvents. One may also utilize oxidizing agents such as pyridinium chlorochromate, pyridinium dichromate, pyridine-sulfurtrioxide or periodinane in an organic solvent such as dichloromethane, chloroform for the oxidation of a compound of Formula II to form a compound of Formula III. 5 Thus, the oxidation of a compound of Formula II can be carried out utilizing dimethyl sulphoxide and acetic anhydride to furnish a compound of Formula III.

The reaction of a compound of Formula III with hydroxylamine hydrochloride to form a compound of Formula IV can be carried out in an organic solvent such as ethanol,

methanol, propanol or isopropyl alcohol, in the presence of an organic base such as pyridine, triethylamine or diisopropylethylamine.

The reduction of a compound of Formula IV to yield a compound of Formula V can be carried out in an organic solvent such as tetrahydrofuran, dimethylformamide, diethylether or dioxane, with a reducing agent such as lithium aluminium hydride or sodium borohydride.

The reaction of a compound of Formula V with an isocyanate or isothiocyanate of Formula VI to yield a compound of Formula VII can be carried out in an organic solvent such as acetonitrile, dichloromethane, dichloroethane, chloroform or carbon tetrachloride. Alternatively, a compound of Formula VII can also be prepared by reacting a compound of Formula V with an appropriate amine in the presence of reagents such as carbonyldiimidazole (CDI) or with carbamates such as phenyl carbamate or p-nitrophenyl carbamate of an amine. Also, optionally thiocarbonyldiimidazole or an isothiocyanate can be used in place of carbonyldiimidazole or isocyanate, respectively in the reaction. Particular illustrative compounds prepared following Scheme I include:

l,2;5,6-Di-0-isopropylidene-3-deoxy-3-[{(4-chloro-phenyl) -amino}-carbonyl]- amino-α-D-allofuranoside (Compound No. 1);

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[{(4-methoxy-phenyl )-amino}-carbonyl]- amino-α-D-allofuranoside (Compound No. 3);

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[{phenyl-sulphonyla mino}-carbonyl]- amino-α-D-allofuranoside (Compound No. 5);

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[{(4-methyl-phenyl) -sulphonylamino}- carbonyl]-amino-α-D-allofuranoside (Compound No. 7);

l,2;5,6-Di-0-isopropylidene-3-deoxy-3-[{(4-nitro-phenyl)- amino}-carbonyl]- amino-α-D-allofuranoside (Compound No. 9);

l,2;5,6-Di-0-isopropylidene-3-deoxy-3-[{4-methylphenyl}-a mino}-carbonyl]- amino-α-D-allofuranoside (Compound No. 11);

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[{(4-trifluoromethyl-p henyl)-amino}- carbonyl]-amino-α-D-allofuranoside (Compound No. 47);

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-{[(2-phenylethyl)-a mino]thiocarbonyl}- amino-α-D-allofuranoside (Compound No. 49);

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-{[(4-fluorophenyl)- amino]thiocarbonyl}- amino-α-D-allofuranoside (Compound No. 50).

An alternative route for the synthesis of compounds of Formula VII is outlined in Scheme II below:

Scheme I

VIII

Formula IX

Vl

Formula V Formula VII

Thus, a compound of Formula II (wherein Ri, R ₂ , R ₄ and R ₅ are the same as defined earlier) can be reacted with a compound of Formula VIII [wherein L is a leaving group such as tosyl or mesyl and hal is a halogen (Cl, Br, I)] to form a compound of Formula IX, which can be reacted with sodium azide to form a compound of Formula X, which can undergo reduction to yield a compound of Formula V, which can be reacted

with a compound of Formula VI (wherein X is O or S and R _x is the same as defined earlier) to furnish a compound of Formula VII.

A compound of Formula II can be reacted with a compound of Formula VIII to form a compound of Formula IX in the presence of an organic base, such as pyridine, triethylamine or diisopropylethylamine.

Alternatively, the hydroxyl group in a compound of Formula II can also be converted to a triflyl group with triflic anhydride.

A compound of Formula IX can be reacted with sodium azide in an organic solvent such as dimethylformamide, tetrahydrofuran, dioxane or diethyl ether. Alternatively, one may also use trimethylsilyl azide or lithium azide in place of sodium azide. Similarly one may also use benzyl amine in place of azido moiety, which on debenzylation would furnish a compound of Formula V.

A compound of Formula X can be reduced to give a compound of Formula V in an organic solvent such as tetrahydrofuran, dioxane, ethanol or diethyl ether, with a reducing agent such as lithium aluminum hydride or sodium borohydride.

Alternatively, the reduction of a compound of Formula X can also be carried out by hydrogenation in the presence of catalytic palladium on carbon.

A compound of Formula V can be reacted with a compound of Formula VI to yield a compound of Formula VII in an organic solvent such as acetonitrile, dichloromethane, dichloroethane, chloroform or carbon tetrachloride.

Also, the alternate strategies mentioned in Scheme I are applicable for the syntheses of compounds of Formula VII.

Compounds prepared following Scheme II are:

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-([{4-(2-methoxy-2-o xoethyl)-phenyl}- amino]- carbonyl)-amino-α-D-glucofuranoside (Compound No. 4);

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-([{4-(2-hydroxy-2-o xoethyl)-phenyl}- amino]-carbonyl)-amino-α-D-glucofuranoside (Compound No. 6);

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[{(4-methyl-phenyl)-am ino}-carbonyl]- amino-α-D-glucofuranoside (Compound No. 8);

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[{(4-chloro-phenyl) -amino}-carbonyl]- ' amino-α-D- glucofuranoside (Compound No. 10);

l^jS _j β-Di-O-isopropylidene-S-deoxy-S-tphenyl-amino-carbony lj-amino-α-D- glucofuranoside (Compound No. 12);

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[{(4-nitro-phenyl)- amino}-carbonyl]- amino-α-D-glucofuranoside (Compound No. 14);

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[{(4-fluoro-phenyl) -amino}-carbonyl]- amino-α-D-allofuranoside (Compound No. 51).

Scheme III

A compound of Formula XI can be prepared following Scheme III. Thus, a compound of Formula II (wherein Ri, R ₂ , R ₄ and R ₅ are the same as defined earlier) can be reacted with a compound of Formula VI (wherein X is O or S and R _x is the same as defined earlier) to form a compound of Formula XI.

A compound of Formula II can be reacted with a compound of Formula VI to furnish a compound of Formula XI in an organic solvent such as dichloromethane, dichloroethane, chloroform or carbon tetrachloride.

Compounds prepared following Scheme III are:

l,2;5,6-Di-O-isopropylidene-3-O-[(4-fluoro-phenyl)-amino] -carbonyl]-α-D- glucofuranoside (Compound No. 48);

l,2;5,6-Di-O-isopropylidene-3-O-[(4-methyl-phenyl)-amino]-ca rbonyl]-α-D- glucofuranoside (Compound No. 13);

l,2;5,6-Di-0-isopropylidene-3-0-[(4-methoxy-phenyl)-amino ]-carbonyl-α-D- glucofuranoside (Compound No. 15);

l,2;5,6-Di-O-isopropylidene-3-O-[(4-chloro-phenyl)-amino] -carbonyl-α-D- glucofuranoside (Compound No. 16).

Scheme IV

Formula XII Formula XIII Formula XIV

Formula XV

Formula XVI

A compound of Formula XVI can be prepared by Scheme IV. Thus, a compound of Formula XII (wherein Ri, R ₂ , R ₄ and R ₅ are the same as defined earlier and r is an integer from 1 to 3) can be reacted with a compound of Formula VIII [wherein L is a leaving group such as mesyl or tosyl and hal is a halogen (Cl, Br, I)] to form a compound of Formula XIII, which can be reacted with sodium azide to form a compound of Formula XIV, which can undergo reduction to give a compound of Formula XV, which can be reacted with a compound of Formula VI to furnish a compound of Formula XVI.

A compound of Formula XII can be reacted with a compound of Formula VIII to form a compound of Formula XIII in the presence of a base such as pyridine, triethylamine or diisopropylethylamine, in an organic solvent selected from the group such as dichloromethane, tetrahydrofuran or dimethylformamide. Thus for example, a

compound of Formula XII can be reacted with p-toluenesuphonyl chloride to form the tosyl compound, a compound of Formula XIII.

A compound of Formula XIII can be reacted with sodium azide to form a compound of Formula XIV in an organic solvent such as dimethylformamide, tetrahydrofuran, dioxane or diethyl ether.

A compound of Formula XIV can be reduced to yield a compound of Formula XV in an organic solvent such as tetrahydrofuran, dimethylformamide, dioxane or diethyl ether, with a reducing agent such as lithium aluminum hydride, sodium borohydride.

Alternatively, a compound of Formula XV can also be prepared by hydrogenation of a compound of Formula XIV in the presence of palladium on carbon.

A compound of Formula XV can be reacted with a compound of Formula VI in a organic solvent selected from, for example, dichloromethane, dichloroethane, carbon tetrachloride or chloroform.

Alternative methods as provided for the synthesis of a compound of Formula VII in Scheme I, are also applicable for the synthesis of a compound of Formula XVI.

Compounds prepared following Scheme IV are:

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[2-{3-(4-chloro-phe nyl)-ureido}-ethyl]-α- D-allofuranoside (Compound No. 2);

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[2-{3-(4-methyl-phe nyl)-ureido}-ethyl]-α- D-allofuranoside (Compound No. 17);

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-{2-[3-(4-methoxy-ph enyl)-ureido]-ethyl}- α-D-allofuranoside (Compound No. 18).

Scheme V

Formula XlX

Compounds of Formula XIX can be prepared by Scheme V. Thus, a compound of Formula XVII (wherein R ₂ , R3, R ₄ and R ₅ are the same as defined earlier, r is an integer from 1 to 3 and hal is (Cl, Br, I) can be reacted with a compound of Formula XVIII (wherein G ₃ is a heterocyclyl ring attached to H through N) to yield a compound of Formula XIX.

A compound of Formula XVII can be reacted with a compound of Formula XVIII to form a compound of Formula XIX in an organic solvent such as dimethylformamide, tetrahydrofuran, dioxane or diethyl ether, in the presence of a base such as potassium carbonate, sodium bicarbonate, triethyl amine, pyridine or diisopropylethylamine. Compounds prepared following Scheme V are:

2,3;5,6-Di-O-isopropylidene-l-O-{3-[l-(4-[3-chloro-phenyl ]-piperazinyl)]- propyl}-α-D-mannofuranoside (Compound No. 29);

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-[4-chloro-phenyl ]-piperazinyl)]-ethyl}- α-D-mannofuranoside (Compound No. 30);

2,3;5,6-Di-0-isopropylidene-l-0-{2-[l-(4-[4-methoxy-pheny l]-piperazinyl)]- ethyl}-α-D-mannofuranoside (Compound No. 31);

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-[2-pyrimidinyl]- piperazinyl)]-ethyl}-α- D-mannofuranoside (Compound No. 32);

2,3 ;5 ,6-Di-O-isopropylidene- 1 -O- {2-[4-morpholinyl] -ethyl } -α-D- mannofuranoside (Compound No. 33);

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-benzyl-piperazin yl)]-ethyl}-α-D- mannofuranoside (Compound No. 34);

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-[4-chloro-phenyl -amino-carbonyl]- piperazinyl)]-ethyl}-α-D-mannofuranoside (Compound No. 35);

2,3 ;5 ,6-Di-O-isopropyli dene- 1 -O- {2-( 1 -piperazinyl)-ethyl} -α-D-mannofuranoside (Compound No. 36).

SCHEME Vl

Formula XXV

Compounds of Formulae XXII, XXIII and XXV can be prepared by Scheme VI.

Path a: A compound of Formula XX (wherein r, R ₂ , R ₃ , R ₄ , R ₅ are the same as defined earlier) can reacted with a compound of Formula XXI (wherein Z is a halogen (Cl, Br, I) or OH, Y and R _u are the same as defined earlier) to yield a compound of Formula XXII.

Path b: A compound of Formula XX can be reacted with a compound of Formula VI (wherein X is O or S and R _x is the same as defined earlier) to form a compound of Formula XXIII.

Path c: A compound of Formula XX can be reacted with a compound of Formula XXIV (wherein R _v is alkyl and hal (Cl, Br, I) to form a compound of Formula XXV.

A compound of Formula XX (Path a) can be reacted with a compound of Formula XXI [when Y is -C(=0)] to furnish a compound of Formula XXII an organic solvent such as dichloromethane, dichloroethane, carbon tetrachloride or chloroform, in the presence of an organic base such as triethylamine, pyridine or diisopropylamine.

Alternatively, when Y is -C(=0), a compound of Formula XX may react with "an activated derivative of a carboxylic acid" to furnish a compound of Formula XXII.

A compound of Formula XX (Path b) can be reacted with a compound of Formula VI to yield a compound of Formula XXIII in an organic solvent such as dichloromethane, chloroform, carbon tetrachloride or tetrahydrofuran.

Alternative methods as provided for the synthesis of a compound of Formula VII in Scheme I, are also applicable for the synthesis of a compound of Formula XXIII.

A compound of Formula XX (Path c) can be reacted with a compound of Formula XXIV to form a compound of Formula XXV in the presence of a base such as potassium carbonate, sodium bicarbonate, triethylamine, pyridine or diisopropylethylamine, in an organic solvent such as dimethylformamide, tetrahydrofuran, dioxane or diethyl ether. Compounds prepared following Scheme VI, path a are:

2,3 ;5 ,6-Di-O-isopropylidene- 1 -O- {2-[ 1 -(4- {4-methyl-phenyl-sulphonyl } - piperazinyl)]-ethyl}-α-D-mannofuranoside (Compound No. 40);

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-[2-thienyl-methy l-carbonyl]- piperazinyl)]-ethyl}-α-D-mannofuranoside (Compound No. 42);

2,3;5,6-Di-O-isopropylidene-l -O- {2-[ 1 -(4-[4-fluoro-phenyl-carbonyl]- piperazinyl)] -ethyl }-α-D-mannofuranoside (Compound No. 43);

Compounds prepared following Scheme VI, path b are:

2,3 ;5,6-Di-O-isopropylidene- 1 -O- {2- [ 1 -(4- {(1 -naphthyl)-amino-carbonyl} - piperazinyl)]-ethyl}-α-D-mannofuranoside (Compound No. 39);

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-[isopropylamino- thiocarbonyl]- piperazinyl)] -ethyl }-α-D-mannofuranoside (Compound No. 38);

Compounds prepared following Scheme VI, path c are:

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-{[3,3']-bithioph enyl-5-ylmethyl}- piperazinyl)]-ethyl}-α-D-mannofuranoside (Compound No. 37);

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-[(2-chloro-3,4-meth ylenedioxy- phenyl)-methyl]-piperazinyl)]-ethyl}-α-D-mannofuranoside (Compound No. 45).

SCHEME VII

HOR ₃ XXlX

Formula XXX Formula XXVI

Formula XXVIII

Compounds of Formula XXVIII and XXX can be prepared by Scheme VII.

Path a: A compound of Formula XXVI (wherein R ₂ , R ₃ , R ₄ and R ₅ are the same as defined earlier and r is an integer from 1 to 3) can reacted with a compound of Formula XXVII (wherein R ₁ and R _m are the same as defined earlier) to form a compound of Formula XXVIII. Path b: A compound of Formula XXVI can be reacted with a compound of Formula XXIX (wherein R _s is the same as defined earlier) to give a compound of Formula XXX

A compound of Formula XXVI (path a) can be reacted with a compound of Formula XXVII to form a compound of Formula XXVIII in the presence of a base such as potassium carbonate, sodium bicarbonate, triethylamine, pyridine or diisopropylethylamine in an organic solvent such as dimethylformamide, tetrahydrofuran, diethyl ether, or dioxane.

A compound of Formula XXVI (path b) can be reacted with a compound of Formula XXIX to form a compound of Formula XXX in the presence of a base such as potassium hydroxide, cesium carbonate, potassium carbonate, sodium hydride, potassium tert-butoxide, in an organic solvent such as dimethylformamide, tetrahydrofuran, dioxane and diethyl ether.

Compounds prepared following Scheme VII, path a are

2,3 ;5 ,6-Di-O-isopropylidene- 1 -O- {2-[ 1 -(4-[2-(2,6-dioxo- 1 -piperidinyl)-acetyl]- piperazinyl)]-ethyl}-α-D-mannofuranoside (Compound No. 41)

2,3 ;5 ,6-Di-O-isopropylidene- 1 -O- {2-[ 1 -(4- {2-( 1 -[ 1 H- 1 ,2,4-triazolyl])-acetyl} - piperazinyl]-ethyl}-α-D-mannofuranoside (Compound No. 44)

Compounds prepared following Scheme VII, path b are

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-{2-[4-chloro-phe noxy]-acetyl}- piperazinyl)]-ethyl}-α-D-mannofuranoside (Compound No. 46)

SCHEME VIII

Hydrolysis Formula XXXII

A compound of Formula XXXII, can be prepared by Scheme VIII. Thus, a compound of Formula XXXI (wherein R ₃ is the same as defined earlier) is hydrolysed to yield a compound of Formula XXXII.

A compound of Formula XXXI is hydrolyzed with the reagents, for example aqueous perchloric acid, aqueous acetic acid, aqueous sulphuric acid or Dowex 50W-8X (commercially available) to form a compound of Formula XXXII in an organic solvent such as methanol, tetrahydrofuran, dimethylformamide, dioxane or diethyl ether.

Compounds prepared following Scheme VIII are:

l,2-0-Isopropylidene-3-deoxy-3-{[(4-methoxy-phenyl)-amino ]-carbonyl}-amino- α-D-allofuranoside (Compound No. 19);

l,2-O-Isopropylidene-3-deoxy-3-{2-[3-(4-methoxy-phenyl)-urei do]-ethyl}-α-D- allofuranoside (Compound No. 20);

1 ,2-O-Isopropylidene-3-O- {(4-chloro-phenyl)-amino} -carbonyl-α-D- allofliranoside (Compound No. 21);

1 ,2-O-Isopropylidene-3-deoxy-3- {[(4-nitτo-phenyl)-amino]-carbonyl} -amino-α-D- allofuranoside (Compound No. 22);

l,2-O-Isopropylidene-3-deoxy-3-{[(4-chloro-phenyl)-amino] -carbonyl}-amino-α- D-allofuranoside (Compound No. 23);

1 ,2-O-Isopropylidene-3-O- {(4-methyl-phenyl)-amino} -carbonyl-α-D- allofuranoside (Compound No. 24);

l,2-O-Isopropylidene-3-deoxy-3-[2-{3-(4-methyl-phenyl)-ur eido}-ethyl]-α-D- allofuranoside (Compound No. 25);

l,2-0-Isopropylidene-3-deoxy-3-{2-[3-(4-{2-methoxy-2-oxo- ethyl}-phenyl)- ureido]-ethyl}-α-D-allofuranoside (Compound No. 26);

l,2-O-Isopropylidene-3-deoxy-3-{2-[(4-methyl-phenyl)-amin o]-carbonyl}-amino- α-D-allofuranoside (Compound No. 27);

l,2-O-Isopropylidene-3-deoxy-3-{2-[3-(4-{2-hydroxy-2-oxo- ethyl}-phenyl)- ureido]-ethyl}-α-D-allofuranoside (Compound No. 28).

SCHEME IX

II

(Formula V

Formula XXXVI

The compounds of the Formula XXXIV and the Formula XXXVI can be prepared by Scheme IX, thus

Path a: the compound of Formula V (wherein Ri, R ₂ , R ₄ and R ₅ are the same as defined earlier) can be reacted with a compound of Formula XXXIII (wherein R _u is the same as defined earlier) to form a compound of Formula XXXIV.

Path b: the compound of the Formula V can be reacted with a compound of Formula XXXV (wherein L is a leaving group such as halogen) to form a compound of Formula XXXVI.

The compound of Formula V (path a) can be reacted with a compound of Formula XXXIII to form a compound XXXIV in an organic solvent such as dichloromethane, carbon tetrachloride, tetrahydrofuran or dimethylformamide, in the presence of an organic base such as triethylamine, pyridine, or diisopropoylethylamiine.

The compound of Formula V (path b) can be reacted with a compound of Formula XXXV in a organic solvent such as acetone, tetrahydrofuran, dimethylformamide, acetonitrile or dimethylsulphoxide, in the presence of a base such as potassium carbonate, sodium bicarbonate, triethylamine or pyridine. Compounds prepared following Scheme IX, path a are:

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-{[4-fluoro-phenyl]s ulphonyl}-amino-α-D- allofuranoside (Compound No. 52);

l,2;5,6-Di-0-isopropylidene-3-deoxy-3-{[4-methyl-phenyl]- sulphonyl}-amino-α- D-allofuranoside (Compound No. 53);

1 ,2;5,6-Di-O-isopropylidene-3-deoxy-3- {[(4-[2-methoxy-2-oxo-ethyl]-phenyl)- amino]-carbonyl}-methylamino-α-D-allofuranoside (Compound No. 54).

Also, in all the above representative examples wherever esters are specified, one skilled in the art could optionally hydrolyze them to their respective acids, for example hydrolysis of alkyl esters (such as ethyl, methyl or benzyl ester) to their corresponding acids can be carried out in the presence of a base, for example, lithium hydroxide, sodium hydroxide or potassium hydroxide. Alternatively, hydrolysis of benzyl ester can be carried out hydrogenatically using catalysts, for example, palladium on carbon or platinum on carbon. Esters such as tert-butyl can be hydrolyzed to their corresponding acids in the presence of acid, for example, trifluoroacetic acid or hydrochloric acid. In the above schemes, where specific bases, acids, solvents, condensing agents, hydrolyzing agents, etc., are mentioned, it is to be understood that other acids, bases, solvents, condensing agents, hydrolyzing agents, etc., may also be used. Similarly, the reaction temperature and duration of the reactions may be adjusted according to the requirements that arise during the process. Particular compounds being produced by Schemes I through IX are listed in Tables

I, II and III.

Table I

Formula I

(wherein Ri & R ₂ and R ₄ & Rs together form isopropylidene groups).

* Represent the isomer of Compound No. 11 ** Represent the isomer of Compound No. 01 *** Represent the isomer of Compound No. 9

Table II

Formula I

(wherein Ri and R ₂ together form an isopropylidene group and R ₄ =Rs=H))

Table III

Formula I

(wherein R ₂ & R _e (when R ₃ is OR ₂ ) and R ₄ & R ₅ together form isopropylidene groups)

Examples set forth general synthetic procedures for the preparation of representative compounds. The examples are provided to illustrate particular aspect of the disclosure and do not be limit the scope of the present invention.

EXAMPLES

Example A: Synthesis of l,2;5,6-Di-O-isopropylidene-3-deoxy-3-amino-oc-D- allofuranoside

Step a: Synthesis of l,2;5,6-di-0-isopropylidene-3-oxo-α-D-glucofuranoside To diacetoneglucose (25g) (commercially available) was added dimethyl sulphoxide (100ml) and acetic anhydride (50ml). The reaction mixture was stirred at 50- 60 ⁰ C for 24 hours. Dimethyl sulphoxide was evaporated under reduced pressure and water (2.5ml) was added with vigorous stirring followed by the addition of ether (10ml) and hexane. The mixture was kept in refrigerator for overnight. The solid thus separated was filtered to obtain the title compound (16g).

Step b: Synthesis of l,2;5,6-di-0-isopropylidene-3-deoxy-3-hydroxyimino-α-D- glucofuranoside

To a compound from step a above (12g), was added hydroxylamine hydrochloride (2.5g) pyridine (100ml) and anhydrous ethanol (100ml) at room temperature. The reaction mixture was stirred for half an hour .The temperature of the reaction was raised to 75 ⁰ C and the reaction mixture was stirred for 24 hours. The solvents were evaporated off under reduced pressure and the residue thus obtained was poured into ice cold water. The organic product was extracted with ethyl acetate followed by washing with water, brine and dried over anhydrous sodium sulphate. The solvent was evaporated under reduced pressure and the product was purified by column chromatography using 25% ethyl acetate in hexane as eluent to furnish the title compound (8.5g).

Step c: Synthesis of l^Sjό-Di-O-isopropylidene-S-deoxy-S-amino-oc-D- allofuranoside

To a suspension of lithium aluminum hydride (8.4g) in tetrahydrofuran (50 ml) at 0 ⁰ C, was added the compound obtained from step b above (8.5g in 50ml tetrahydrofuran) with constant stirring. After complete addition, the reaction mixture was allowed to attain room temperature and stirred for 8 hours. The excess of lithium aluminum hydride was decomposed by addition of ethyl acetate (100 ml) followed by the addition of water and sodium hydroxide solution (2ml, 15%) dropwise at 0 ⁰ C .The reaction mixture was filtered off, washed with warm ethyl acetate and dried over anhydrous sodium sulphate. The

solvent was evaporated under reduced pressure and the crude compound was purified by column chromatography using 50% methanol in ethyl acetate as eluent to furnish the title compound (7.Og)

Example B: Synthesis of l,2;5,6-Di-O-isopropylidene-3-deoxy-3-hvdroxyethyl-oc-D allofuranoside

Step a:-Synthesis of l,2;5,6-di-0-isopropylidene-3-oxo-α-D-glucofuranoside

To diacetone glucose (25g) (commercially available) was added dimethyl sulphoxide (100 ml) and acetic anhydride (50ml) .The reaction mixture was stirred at 50- 60 ⁰ C for 24 hours. Dimethyl sulphoxide was evaporated under reduced pressure and water was added with constant stirring followed by the addition of ether (10ml) and hexane. The mixture was kept in refrigerator for overnight and the solid thus separated was filtered to obtain the title compound (16g).

Step b: Synthesis of l,2;5,6-di-0-isopropylidene-3-deoxy-3-(methoxycarbonyl- methylene)-α-D-glucofuranoside

The ice-cold solution of trimethyl phosphonoacetate (34ml) in dimethylformamide (34ml), was added potassium tert-butoxide (8.5g) and the reaction mixture was stirred at room temperature for 10 minutes. To it was added a solution of the compound (17g) obtained from the step a above in dimethyl formamide (34ml) and the reaction mixture was stirred for 1 hour at 0-10 ⁰ C. The solvent was evaporated under reduced pressure and the residue was taken in water and extracted with ether followed by washing with water and brine. The mixture was dried over anhydrous sodium sulphate and the solvent was evaporated under reduced pressure. The crude compound thus obtained was taken in hexane and the mixture was kept in refrigerator for overnight. After trituration, the solid was separated out which was filtered and dried. The compound was purified by column chromatography using to furnish the title compound (1 Ig).

Step c: Synthesis of l,2;5,6-di-0-isopropylidene-3-deoxy-3-(methoxycarbonyl- methyl)-α-D-allofuranoside

To a solution of a compound obtained from step b above (1 Ig) in methanol (100ml) at 0-5 ⁰ C, was added sodium borohydride (2.5g) in small portion with continuous stirring. The reaction mixture was stirred for one hour. The reaction mixture was allowed to come to room temperature followed by stirring for 24 hours. Acetone (10ml) was added to the reaction mixture to decompose excess of sodium borohydride. Methanol was removed under reduced pressure. The organic product was extracted with chloroform followed by washing with water, and brine. The reaction mixture was dried over anhydrous sodium sulphate. The solvent was evaporated under reduced pressure and the syrup thus obtained was taken in hexane, which on scratching gave solid product, which was filtered and dried. The crude compound was purified by column chromatography using 10% ethyl acetate in hexane as eluent (9g).

Step d: Synthesis of l,2;5,6-di-0-isopropylidene-3-(2-hydroxyethyl)-α-D- allofuranoside

To a suspension of lithium aluminum hydride (5.7g) in tetrahydrofuran (50ml) at 0 ⁰ C, was added a solution of the compound (16g) obtained from step c above in tetrahydrofuran (50ml) dropwise with constant stirring. After complete addition the reaction mixture was allowed to attain room temperature and stirred for 8 hours. The excess of lithium aluminum hydride was decomposed by adding ethyl acetate (100ml) followed by the addition of water and aqueous sodium hydroxide solution (2ml, 15%) at 0 ⁰ C. The reaction mixture was filtered, washed with warm ethyl acetate and dried over anhydrous sodium sulphate. The solvent was evaporated under reduced pressure and the crude product was purified by column chromatography using 20% methanol in ethyl acetate as eluent to furnish the title compound (1.Ig).

Example C: Synthesis of l,2;5,6-di-O-isopropylidene-3-deoxy-3-ethylamino-α-D- allofuranoside

Step a: Synthesis of l,2;5,6-di-0-isopropylidene-3-deoxy-3-[2-(4-methyl-phenyl- sulphonyloxy)-ethyl]-α-D-allofuranoside

To a solution of l,2;5,6-Di-O-isopropylidene-3-hydroxyethyl-oc-D-allofuranosi de (1 Ig) in pyridine (15ml) was added a solution of p-toluenesulphonyl chloride (5.5g) in

pyridine (15 ml) at 0 ⁰ C with constant stirring .The reaction mixture was stirred for 6 hours. The temperature of the reaction mixture was gradually raised to 5°C and stirred for 12 hours. The reaction mixture was diluted with water. The solvents were evaporated off under reduced pressure and extracted with ethyl acetate followed by washing with water and brine and dried over anhydrous sodium sulphate. The solvent was evaporated under reduced pressure and the crude product was purified by column chromatography using 30% ethyl acetate in hexane as eluent to furnish the title compound. (9g).

Step b: Synthesis of l,2;5,6-di-0-isopropylidene-3-deoxy-3-[2-azidoethyl]-α-D- allofuranoside To a suspension of the compound obtained from step a above (9g) in dimethylformamide (50 ml), was added sodium azide (1.58g). The reaction mixture was heated at 130 ⁰ C for 8-10 hours. Dimethylformamide was evaporated under reduced pressure and the compound was extracted with ethyl acetate followed by washing with sodium bicarbonate, water, brine and dried over anhydrous sodium sulphate. The solvent was evaporated under reduced pressure to furnish the title product (3.5g).

Step c: Synthesis of l,2;5,6-di-0-isopropylidene-3-deoxy-3-ethylamino-α-D- allofuranoside

To a suspension of lithium aluminum hydride (1.Og) in tetrahydrofuran (50 ml) at O ⁰ C was added a solution of the compound (4g) obtained from step b above in tetrahydrofuran (20ml) dropwise at O ⁰ C with constant stirring. After complete addition, the reaction mixture was allowed to attain room temperature and stirred for 8 hours. The excess of lithium aluminum hydride was decomposed by adding ethyl acetate (100ml) followed by the addition of water and sodium hydroxide solution (2ml, 15%) at 0 ⁰ C. The reaction mixture was filtered washed with warm ethyl acetate, the filtrate was dried over anhydrous sodium sulphate. The solvent was evaporated under reduced pressure and the product was purified by column chromatography using 20% methanol in ethyl acetate as eluent to give the desired product (2.8 g).

Scheme I

Example 1 : Synthesis of 1.2;5,6-Di-O-isopropylidene-3-deoxy-3-ri(4-trifluoromethyl- phenylVamino} -carbonyl] -amino-α-D-allofuranoside (Compound No.47) 4-Trifluoromethyl-phenyl isocyanate (144mg) was added slowly to a solution of

1 ,2;5,6-di-O-isopropylidene-3-deoxy-3-amino-α>D-allofuran oside (200mg) in dichloromethane (10 ml) at 0-5 ⁰ C with constant stirring. After complete addition the reaction mixture was allowed to come to room temperature and stirred for 2 hours. The solvents were evaporated under reduced pressure and the crude product was purified by column chromatography using 50% ethyl acetate in hexane as eluent to furnish the title compound (340mg).

¹ H NMR (CDCl ₃ ) (300 MHz):δ 7.44-7.55(4H,m), 6.89(lH,s), 5.85(lH,s), 5.20(lH,d, 9Hz), 4.68(lH,m), 4.29(lH,m), 4.13(2H,m), 4.01(lH,m), 3.89(lH,m), 1.55(3H,s), 1.45(3H,s), 1.35(6H,s). Analogues of 1 ,2;5,6-Di-O-isopropylidene-3-deoxy-3-[ {(4-trifluoromethyl- phenyl)-amino}-carbonyl]-amino-α-D-allofuranoside (Compound No.47) can be prepared by replacing appropriate isocyanate, respectively, as applicable in each case.

1,2; 5 ,6-Di-O-isopropylidene-3 -deoxy-3 - [ {(4-chloro-phenyl)-amino } -carbonyl] - amino-α-D-allofuranoside (Compound No. 1)

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[{(4-methoxy-phenyl )-amino}-carbonyl]- amino-α-D-allofuranoside (Compound No. 3)

1 ,2 ; 5 ,6-Di-O-isopropylidene-3 -deoxy-3 -[ {phenyl-sulphonylamino } -carbonyl] - amino-α-D-allofuranoside (Compound No. 5)

l,2;5,6-Di-0-isopropylidene-3-deoxy-3-[{(4-methyl-phenyl) -sulphonylamino}- carbonyl]-amino-α-D-allofuranoside (Compound No. 7)

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[{(4-nitro-phenyl)- amino}-carbonyl]- amino-α-D-allofuranoside (Compound No. 9)

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[{(4-methyl-phenyl)-am ino}-carbonyl]- amino-α-D-allofuranoside (Compound No. 11)

Example 2: Synthesis of l,2;5,6-Di-O-isopropylidene-3-deoxy-3-(|Y2-phenylethyl)- aminolthiocarbonvU-amino-α-D-allofuranoside (Compound No. 49) To a solution of the compound l,2;5,6-Di-isopropylidene-3-deoxy-α-Z>- allofuranoside (lOOmg) in dichloromethane (5ml), was added triethylamine (0.06 ml) and 2-phenyl isocyanate (43mg) at room temperature. The reaction mixture was stirred for 4 hours at 55 ⁰ C. Solvent was evaporated under reduced pressure. The crude compound thus obtained was purified with 50% ethyl acetate in hexane as eluent to furnish the title compound ( 1 OOmg) .

¹ H NMR (CDCl ₃ ) (300 MHz):δ 7.35-7.21(5H,m), 6.13(lH,bs), 5.92(lH,bs), 5.82(lH,d, 3.6Hz), 4.68(lH,t, 8.7Hz), 4.52(lH,bs), 4.27(lH,q, 10.5 Hz), 4.16(lH,t, 6.6Hz), 4.00- 3.88(2H,m), 3.60-3.80(2H,m), 2.92(2H,t, 5.7Hz), 1.55(3H,s), 1.41(3H,s), 1.33(6H,s)

Analogues of l,2;5,6-Di-0-isopropylidene-3-deoxy-3-{[(2-phenylethyl)-amin o]- thio-carbonyl}-amino-oc-D-allofuranoside (Compound No. 49) described below, can be prepared by replacing appropriate isothiocyanate group in place of 2-phenyl isocyanate, respectively, as applicable in each case

l,2;5,6-Di-0-isopropylidene-3-deoxy-3-{[(4-fluorophenyl)- amino]-thio-carbonyl}- amino-α-D-allofuranoside (Compound No. 50)

Scheme II

Example 3: Synthesis of l,2;5,6-Di-O-isopropylidene-3-deoxy-3-([{4-(2-methoxy-2-oxo- ethvD-phenyll-aminol-carbonvD-amino-α-D-glucofuranoside (Compound No. 4)

Step a: Synthesis of l,2;5,6-Di-0-isopropylidene-3-0-tosyl-α-D-glucofuranoside To a solution of diacetoneglucose (8 g) (commercially available) in pyridine (20 ml) was added a solution of p-toluenesulphonyl chloride (4 g) in pyridine (20 ml) at 0°C.The reaction mixture was stirred for 8-10 hours. The solvent was evaporated under

reduced pressure and the residue thus obtained was washed with hexane to obtain the title compound (8g).

Step b: Synthesis of l,2;5,6-Di-0-isopropylidene-3-deoxy-3-azido-α-D- glucofuranoside To a solution of a compound obtained from step a above (8 g) in dimethylformamide (50ml) was added sodium azide (1.5g). The reaction mixture was heated at 130 ⁰ C for 10 hours, extracted with ethyl acetate followed by washing with water, brine and dried over anhydrous sodium sulphate. The solvent was evaporated under reduced pressure and the crude product was purified by column chromatography using 30% ethyl acetate in hexane as eluent to furnish the title compound (4 g).

Step c: Synthesis of l,2;5,6-Di-0-isopropylidene-3-deoxy-3-amino-α-D- glucofuranoside

To a solution of lithium aluminum hydride (1.1 g) in tetrahydrofuran (20ml) at 0 ⁰ C, was added the compound obtained from step b (3.5 g) in tetrahydrofuran (10ml). The reaction mixture was stirred at this temperature for 15 minutes, and then was allowed to attain at room temperature and stirred for 10 hours. The reaction mixture was extracted with ethyl acetate followed by washing with aqueous sodium bicarbonate, water and brine and dried over anhydrous sodium sulphate. The solvent was evaporated under reduced pressure and the crude residue was purified by column chromatography using 30% ethyl acetate in hexane as an eluent to furnish the title compound (2 g).

Step d: Synthesis of l,2;5,6-D-0-isopropylidene-3-deoxy-3-([{4-(2-methoxy-2- oxoethyl)-phenyl}-amino]-carbonyl)-amino-α,D-gIucofuranosid e

To a solution of the compound (1 g) obtained from step c above in dichloromethane (10 ml) at 0 ⁰ C was added methyl 4-isocyanatophenyl acetate (0.71 g). The reaction mixture was stirred for 15 minutes at the same temperature. The reaction mixture was allowed to attain room temperature and stirred for 24 hours. The solvent was evaporated under reduced pressure and the crude product was purified by column chromatography using 15% ethyl acetate in hexane as eluent furnish the title compound (1 -3 g)-

¹ H NMR (CDCl ₃ ) (300 MHz):δ 7.35(lH,s), 7.60-7.14(4H,m), 5.95(lH,d,7.5Hz), 5.81(lH,d, 3.3Hz), 4.60(lH,d,3.48Hz), 4.3-4.23(2H,m), 4.16-4.07(2H,m), 3.96(lH,m), 3.68(3H,s), 3.56(2H,s), 1.51(3H,s), 1.4(3H,s), 1.32(3H,s), 1.27(3H,s),

Analogues of 1,2; 5,6-Di-O-isopropylidene-3-deoxy-3-([{4-(2-methoxy-2-oxo- ethyl)-phenyl} -amino]-carbonyl)-amino-α-D-glucofuranoside (Compound No. 4) can be prepared by using appropriate isocyanate in place of methyl-4-isocyanatophenyl acetate

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[{(4-methyl-phenyl) -amino}-carbonyl]- amino-α-D-glucofuranoside (Compound No. 8)

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[{(4-chloro-phenyl) -ammo}-carbonyl]- amino-α-D-glucofuranoside (Compound No. 10)

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[phenyl-amino-carbo nyl]-amino-α-D- glucofuranoside (Compound No. 12)

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-[{(4-nitro-phenyl)- amino}-carbonyl]- amino-α-D-glucofuranoside (Compound No. 14)

1 ,2;5,6-Di-O-isopropylidene-3-deoxy-3-{[(4-fluoro-phenyl)-ami no]-carbonyl}- amino-α-D-allofuranoside (Compound No. 51)

Example 4: Synthesis of l,2;5,6-Di-O-isopropylidene-3-deoxy-3-([{4-(2-hydroxy-2-oxo- ethylVphenyl|-amino1-carbonyl)-amino-α-D-glucofuranoside (Compound No. 6) To a solution of the compound No. 4 (1 g, Example 2) in methanol (100 ml), was added sodium hydroxide (20 ml, IN). The reaction mixture was stirred for 6 hour at 50 ⁰ C. The solvent was evaporated under reduced pressure. The aqueous layer was neutralized with dilute hydrochloric acid. The solid thus obtained was extracted with ethyl acetate followed by washing with water, brine and dried over anhydrous sodium sulphate. The solvent was evaporated under reduced pressure and the crude compound was purified by column chromatography using 10% ethyl acetate in hexane as eluent to furnish the title compound (500mg).

¹ H NMR (CDCl ₃ ) (300 MHz):δ 7.57(1 H,s), 7.17(3H,s), 6.08(lH,bs), 5.85(lH,d, 3.3Hz), 4.63(lH,d, 3.24Hz), 4.24(2H,m), 4.14(3H,m), 4.10(lH,m), 3.56(2H,s), 1.51(3H,s), 1.40(3H,s), 1.33(3H,s), 1.29(3H,s).

Scheme III

Example 5: Synthesis of l,2;5,6-Di-O-isopropylidene-3-O-[(4-fluoro-phenyl)-aminol- carbonyll-α-D-glucofuranoside (Compound No. 48)

To a solution of diacetoneglucose (260mg) in dichloromethane (10ml) at 0 ⁰ C, was added 4-fluorophenyl isocyanate (105mg) and triethylamine (40mg) and then stirred at room temperature for 3-4hours, followed by re fluxing for 3 hours. The volatiles were evaporated under reduced pressure and the crude residue was purified by column chromatography using 20% ethyl acetate in hexane as eluent to furnish the title compound (170mg).

¹ H NMR (CDCl ₃ ) (30OmHz): δ 7.35(2H,bs), 7.02(2H,t, 8.4Hz), 6.65(1H,NH), 5.89(lΗ,d, 3.3Hz), 5.25(lH,s), 4.65(lH,d, 3.6Hz), 4.20-4.25(2H,m), 4.03-4.12(2H,m), 1.53(3H,s), 1.43(3H,s), 1.33(3H,s) and 1.32(3H,s).

Analogues of 1,2; 5,6-Di-O-isopropylidene-3-O-[(4-fluoro-phenyl)-amino]- carbonyl]-α-D-allofuranoside (Compound No. 13) can be prepared by using appropriate isocyanate in place of 4-fluoro-phenyl isocyanate respectively, as applicable in each case.

l,2;5,6-Di-O-isopropylidene-3-O-[(4-methyl-phenyl)-amino] -carbonyl]-α-D- glucofuranoside (Compound No. 13)

l ,2;5,6-Di-O-isopropylidene-3-O-[(4-methoxy-phenyl)-amino]-ca rbonyl-α-D- glucofuranoside (Compound No. 15)

l,2;5,6-Di-O-isopropylidene-3-O-[(4-chloro-phenyl)-amino] -carbonyl-α-D- glucofuranoside (Compound No. 16)

Scheme IV

Example 6: Synthesis of l,2;5,6-Di-O-isopropylidene-3-deoxy-3-f2-l3-( ^' 4-chloro-phenylV ureidol-ethyll-α-D-allofuranoside (Compound No. 2)

To a solution of the compound l,2;5,6-di-0-isopropylidene-3-deoxy-3-ethylamino- oc-D-allofuranoside (200 mg) in dichloromethane (20 ml) at 0-5 ⁰ C, was added a solution of p-chlorophenyl isocyanate (0.12 g) in dichloromethane (10 ml) with constant stirring and the reaction mixture was stirred for 15 minutes. The reaction mixture was allowed to attain room temperature and stirred for 8 hours. The solvent was evaporated under reduced pressure and the crude product was purified by column chromatography using 50% ethyl acetate as eluent to furnish the title compound (150 mg).

¹ H NMR (CDCl ₃ ) (300 MHz):δ 7.74(lH,s), 7.35(2H,m), 7.20(2H,m), 7.35(lH,d, 3Hz),

7.20(2H,m), 5.73(lH,d, 3Hz), 5.59(lH,d, 4.8Hz), 4.72(lH,t, 3.93Hz), 4.07-3.92(3H,m), 3.75(lH,t, 7.4Hz), 3.42-3.3(2H,m), 1.90(3H,m), 1.49(3H,s), 1.4(3H,s), 1.33(3H,s), &1.30(3H,s).

Analogues of 1 ,2;5,6-Di-O-isopropylidene-3-deoxy-3-[2- (3-(4-chloro-phenyl)- ureido} -ethyl] -α-D-allofuranoside (Compound No. 2) can be prepared by using appropriate isocyanate in place of p-chlorophenyl isocyanate, respectively, as applicable in each case

l,2;5,6-Di-0-isopropylidene-3-deoxy-3-[2-{3-(4-methyl-phe nyl)-ureido}-ethyl]-α-

D-allofuranoside (Compound No. 17)

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-{2-[3-(4-methoxy-ph enyl)-ureido]-ethyl}- α-D-allofuranoside (Compound No. 18)

Scheme V

Example 7: Synthesis of 2,3;5,6-Di-O-isopropylidene-l-O-{2-(l-piperazinyl)-ethvU-α- D- mannofuranoside (Compound No. 36)

Step a: Synthesis of l-0-(2-chloroethyl)-2,3;5,6-di-0-isopropylidene-α-D- 5 niannofuranoside

A suspension of mannose (500 mg) in anhydrous acetone (20ml) was cooled to O ⁰ C followed by the addition of sulphuric acid (0.05 ml) and chloroethanol (558 mg). The reaction mixture was refluxed till the reaction showed completion (TLC). The reaction mixture was neutralized with triethylamine and excess of acetone was evaporated under 10 reduced pressure. The residue thus obtained was dissolved in ethyl acetate followed by washing with aqueous sodium bicarbonate and dried over anhydrous sodium sulphate. The solvent was evaporated under reduced pressure and the crude product was purified by column chromatography using 10% ethyl acetate as eluent to furnish the title compound (200mg).

15 Step b: Synthesis of 2,3;5,6-Di-0-isopropylidene-l-0-{2-(l-piperazinyl)-ethyl}-α -D- mannofuranoside (Compound No. 36)

To the compound obtained from the above step a (100 mg) was added a solution of potassium iodide (52mg) in dimethylformamide (5ml). The reaction mixture was stirred at 80 ⁰ C for one hour followed by the addition of piperazine (133mg) and potassium

20 carbonate (86mg). After completion of reaction (TLC) the reaction mixture was poured in cold water and extracted with ethyl acetate .The organic layer was dried over anhydrous

^ sodium sulphate, filtered and evaporated under reduced pressure. The crude residue was purified by column chromatography using 10% methanol in ethyl acetate as eluent to furnish the title compound (60 mg).

25 ¹ H NMR (CDCl ₃ , 300MHz):δ 4.99(1H, s), 4.78-4.75(1H, m), 4.6O(1H, m), 4.39(1H, m), 4.09-4.03(2H, m), 4.95-4.92(1H, m), 3.74(1H, m), 3.55-3.53(1H, m), 2.91(3H, t, 4.89Hz), 2.56(2H, t, 5.8Hz), 2.26(6H, bs), 1.45(6H, s), 1.37(3H, s), 1.31(3H, s).

Analogues of 2,3 ; 5 ,6-Di-O-isopropylidene- 1 -O- {2-( 1 -piperazinyl)-ethyl } -α-D- mannofuranoside (Compound No. 36) can be prepared by replacing appropriate amine in place of piperazine and appropriate sugar moiety respectively, as applicable in each case.

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-[4-methoxy-pheny l]-piperazinyl)]- ethyl } -α-D-mannofuranoside (Compound No . 31 )

2,3 ;5,6-Di-O-isopropylidene- 1 -O- {2-[ 1 -(4-[2-pyrimidinyl]-piperazinyl)]-ethyl} -α- D-mannofuranoside (Compound No. 32)

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-benzyl-piperazin yl)]-ethyl}-α-D- mannofuranoside (Compound No. 34)

2,3;5,6-Di-O-isopropylidene-l-O-{2-[4-morpholinyl]-ethyl} -α-D- mannofuranoside (Compound No. 33)

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-[{4-chloro-pheny l}-aminocarbonyl]- piperazinyl)] -ethyl }-α-D-mannofuranoside (Compound No. 35)

2,3;5,6-Di-O-isopropylidene-l-O-{3-[l-(4-[3-chloro-phenyl ]-piperazinyl)]- propyl} -α-D-mannofuranoside (Compound No. 29)

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-[4-chloro-phenyl ]-piperazinyl)]-ethyl}- α-D-mannofuranoside (Compound No. 30)

Scheme VI, (path a)

Example 8: Synthesis of 2.3;5,6-Di-O-isopropylidene-l-O-(2-[l-(4-[2-thienyl-methyl- carbonyl1-piperazinyl) ^" |-ethvU -α-D-mannofuranoside (Compound No. 42)

To a solution of the compound No. 36 (200 mg) in dichloromethane (10ml) cooled at 0 ⁰ C, was added triethylamine (82mg) and chloroacetylthiophene (104 mg) slowly. The reaction mixture was stirred till the reaction showed completion (TLC). The reaction mixture was poured into ice-cold water and the product was extracted with dichloromethane. The organic layer was dried over anhydrous sodium sulphate and the solvent was evaporated under reduced pressure. The crude product was purified by column

chromatography using 90% ethyl acetate in hexane as eluent to furnish the title compound (90 mg).

¹ H NMR (CDCl ₃ ) (300 MHz):δ 7.21(lH,d, 4.5Hz), 6.96(lH,dd, 4.5Hz), 6.91 (lH,d, 3Hz), 4.99(lH,s), 4.77(lH,t, 4Hz), 4.60(lH,d, 5.8Hz), 4.4 (lH,m), 4.1 l-4.03(2H,m), 3.95(3H,m), 3.73(lH,m), 3.67(2H,bs), 3.53(3H,bs), 2.57(2H,bs), 2.47-2.39(4H,m), 1.48(3H,s), 1.46(3H,s), 1.39(3H,s), 1.33(3H,s).

Analogues of 2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-[2-thienyl-methyl- carbonyl]-piperazinyl)]-ethyl}-α-D-mannofuranoside (Compound No. 42) can be prepared by using appropriate acyl halide group in place of chloroacetylthiophene, respectively, as applicable in each case.

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-[4-fluoro-phenyl -carbonyl]- piperazinyl)] -ethyl }-α-D-mannofuranoside (Compound No. 43)

Example 9: Synthesis of 2,3;5,6-Di-O-isopropylidene-l-O-{2-P-(4-(4-methyl-phenyl- sulphonyll-piperazinyl)] -ethyl } -α-D-mannofuranoside (Compound No. 40)

To a solution of the Compound No.36 (200 mg) in pyridine (5ml), was added p- toluenesulphonyl chloride (122 mg) the reaction mixture was stirred for 2 hours. The reaction mixture was poured into cold water and was extracted with ethyl acetate followed by washing with water, brine and dried over anhydrous sodium sulphate. The solvent was evaporated under reduced pressure and the crude product was purified by column chromatography using 50% ethyl acetate in hexane as eluent to furnish the title compound (130 mg).

¹ H NMR (CDCl ₃ ) (300 MHz):δ 7.64(2H,d, 8Hz), 7.32(2H,d), 4.94(lH,s), 4.74 (lH,t, 3.4Hz), 4.56(lH,d, 5.9Hz), 4.38(lH,m), 4.06(lH,m), 3.99 (lH,m), 3.89(lH,m),

3.87(lH,m), 3.69(lH,m), 3.48(lH,m), 3.02(4H, s), 2.55(6H,s), 2.43(3H,s), 1.44(3H,s), 1.42(3H,s), 1.3(3H,s), 1.26(3H,s).

Scheme VI, (path b)

Example 10: Synthesis of 23;5.6-Di-O-isopropyridene-l-O-(2-ri-(4-m-naphthyl)- amino-carbonvU-piperazinyl)]-ethyl|-α-D-mannofuranoside (Compound No. 39)

To a solution of the Compound No. 36 (200 mg) in acetonitrile (5ml) was added naphthyl isocyanate (109mg). The reaction mixture was stirred at room temperature till the reaction shown completion (TLC). The solvent was evaporated under reduced pressure. The crude product was purified by column chromatography using 90% ethyl acetate in hexane as eluent to furnish the title compound (100 mg).

¹ H NMR (CDCl ₃ ) (300 MHz):δ 7.88(2H,m), 7.68(2H,m), 7.54-7.47(3H,m), 6.67(1 H,s), 5.04(lH,s), 4.80(lH,t, 2.31Hz), 4.64(lH,d, 5.8Hz), 4.40(lH,m), 4.13-4.08(2H,m) 4.00(lH,m), 3.8O(lH,m), 3.60(5H,t), 2.66(2H,m), 2.57(4H,t), 1.49(3H,s), 1.4δ(3H,s), 1.40(3H,s), 1.35(3H,s).

Example 11 : Synthesis of 2,3:5,6-Di-O-isopropylidene-l-O-(2-[l-(4-risopropylamino- thiocarbonyli-piperazinylil-ethvU-α-D-mannofuranoside (Compound No. 38)

To a solution of the Compound No.36 (200 mg) in acetonitrile (5ml) was added p- chlorophenyl isothiocyanate (65mg). The reaction mixture was stirred at room temperature till the reaction showed completion (TLC). The solvent was evaporated under reduced pressure. The crude product was purified by column chromatography using 50% ethyl acetate in hexane as eluent to furnish the title compound (140 mg).

¹ H NMR (CDCl ₃ ) (300 MHz):δ 5.23-5.20(lH,bs), 4.99(lH,s), 4.78-4.75(lH,m), 4.60- ' 4.59(2H,m), 4.41-4.39(lH,m), 4.09-4.03(2H,m), 3.95-3.92(lH,m), 3.80-3.74(5H,m), 3.57- 3.55(lH,m) ,2.61-2.51(6H,m), 1.46(6H,s), 1.37(3H,s), 1.32(3H,s), 1.25(3H,s), 1.24(3H,s).

Scheme VI, (path c)

Example 12: Synthesis of 2,3;5.6-Di-O-isopropylidene-l-O-l2-ri-(4-(r3.3'l-bithioρhen yl- 5-yl-methyl}-piperazinyl)]-ethyU-α-D-marinofuranoside (Compound No. 37)

To a solution of 5-chloromethyl-[3,3']-bithiophenyl (200 mg) in dimethylformamide (5ml) and potassium carbonate (11 lmg) was slowly added the Compound No. 36 (138mg). The reaction mixture was stirred for 3 hours at room temperature and then the reaction mixture was poured into ice-cold water and the product was extracted with ethyl acetate. The organic layer was dried over anhydrous sodium sulphate and evaporated under reduced pressure. The crude product was purified by column chromatography to furnish the title compound (90 mg).

¹ H NMR (CDCl ₃ ) (300 MHz): δ 7.34-7.26(4H,m), 7.15(lH,s), 4.99(lH,s), 4.76(lH,t. 5.61Hz), 4.60(lH,d, 5.8Hz), 4.40 (lH,m), 4.10-3.92 (3H,m), 3.78-3.72 (3H,m), 3.56 (lH,m), 2.58 (10H,bs), 2.04 (IH, s), 1.46(3H,s), 1.45 (3H,s), 1.37 (3H,s), 1.32 (3H,s).

Analogues of 2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-{[3,3']-bithiopheny l-5-yl- methyl}-piperazinyl)]-ethyl}-α-D-mannofuranoside (Compound No. 37) can be prepared by replacing appropriate alkyl halide group in place of 5-chloromethyl-[3, 3 ¹ ]- bithiophenyl, respectively, as applicable in each case.

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-[(2-chloro-3,4-m ethylenedioxy- phenyl)-methyl]-piperazinyl)]-ethyl}-α-D-mannofuranoside (Compound No. 45)

Scheme VII, (path a)

Example 13: Synthesis of 2.3;5.6-Di-O-isopropylidene-l-O-(2-ri-(4-(2-(l-riH-1.2.4- triazolvH)-acetyli-piperazinyl]-ethyl}-α-D-mannofuranoside (Compound No. 44) Step a: Synthesis of 2,3;5,6-Di-0-isopropylidene-l-0-{2-(l-[4-chloroacetyl]- piperazinyl)-ethyl}-α-D-mannofuranoside

To a solution of the Compound No. 36 (2 g) in dichloromethane (35 ml) cooled at 0 ⁰ C, was added triethylamine (1.13 gm) and chloroacetyl chloride (0.51 ml). The reaction

mixture was poured into ice-cold water and the product was extracted with dichloromethane. The solvent was evaporated under reduced pressure. The crude product was purified by column chromatography using 50% ethyl acetate in hexane as eluent to furnish the title compound (1.6 g). Step b: Synthesis of Σ^S.ό-Di-O-isopropylidene-l-O-^^l-^^-α-riH-l^Λ- triazolyφacetyU-piperazinylJ-ethvU-α-D-mannofuranoside

To a solution of the compound obtained from step a above (200 mg) in dimethylformamide (5ml), was added IH-[1, 2,4]-triazole (37 mg) and cesium carbonate (145mg). The reaction mixture was stirred at room temperature till the reaction showed completion (TLC). The reaction mixture was poured into ice-cold water and extracted with ethyl acetate. The organic layer was dried over anhydrous sodium sulphate and filtered. The solvent was evaporated under reduced pressure. The crude compound was purified by column chromatography using 90% ethyl acetate in hexane as eluent to furnish the title compound (12mg). ¹ H NMR (CDCl ₃ ) (300 MHz):δ 8.26(lH,s), 7.98(lH,s), 5.06(2H,s), 5.01(lH,s), 4.79(lH,t, 3.2Hz), 4.62(lH,d,5.9Hz), 4.40(lH,m), 4.12-4.06(2H,m), 3.97(lH,m), 3.80(lH,m), 3.68(2H,bs), 3.57(3H,bs), 2.64-2.60(2H,m), 2.56-2.50(4H,m), 1.49(3H,s), 1.48(3H,s), 1.48(3H,s), 1.40(3H,s), 1.34(3H,s).

Analogues of 2,3 ;5,6-Di-O-isopropylidene- 1 -O- { [ 1 -(4- {2-( 1 -[ 1 H- 1 ,2,4-triazolyl])- acetyl}-piperazinyl] -ethyl }-α-D-mannofuranoside (Compound No. 44) can be prepared by replacing appropriate amine group in place of lH-[l,2,4]-triazole, respectively, as applicable in each case.

2,3;5,6-Di-O-isopropylidene-l-O-{2-[l-(4-[2-(2,6-dioxo-l- piperidinyl)-acetyl]- piperazinyl)]-ethyl}-α-D-mannofuranoside (Compound No. 41)

Scheme VII, (path b)

Example 14: Synthesis of 2.3:5.6-Di-O-isopropylidene-l-O-(2-ri-f4-(2-r4-chloro- phenoxyl-acetyll-piperazinyl)l-ethvU-α-D-mannofuranoside (Compound No. 46)

To a solution of a compound obtained from step a of Example 12 above (200 mg) in dimethylformamide (5 ml), was added cesium carbonate (145 mg) and 4-chlorophenol (69mg). The reaction mixture was stirred at 60 ⁰ C till the reaction completion (TLC). The solvent was evaporated under reduced pressure and the crude product was purified by column chromatography using 50% ethyl acetate in hexane as eluent to furnish the title compound (160 mg). ¹ H NMR (CDCl ₃ ) (300 MHz):δ 7.27(2H,d, 9Hz), 6.90(2H,d, 9Hz), 5.01(lH,s),

4.78(lH,m), 4 ^' 68(2H,s), 4.61(lH,d, 5.8Hz), 4.43 (lH,m), 4.12-4.08(2H,m) 3.97(lH,m), 3.75-3.65(lH,m), 3.59-3.54(5H,m), 2.59(2H,t, 5.8Hz), 2.48(4H,bs), 1.49(3H,s), 1.47(3H,s), 1.40(3H,s), 1.34(3H,s).

Scheme VIII

Example 15: Synthesis of L2-O-isopropylidene-3-deoxy-3-{2-r3-(4-|2-methoxy-2- oxoethvU-phenvD-ureidol-ethvU-α-D-allofuranoside (Compound No. 26)

To a solution of the compound No. 4 (prepared following Scheme II) (4.0 g) in tetrahydrofuran (4 ml) was added aqueous perchloric acid (30%, 4.0 ml) at 0 ⁰ C and stirred the reaction mixture at this temperature for 6 hours. The solvent was evaporated under reduced pressure and the crude compound was purified by column chromatography using 70% ethyl acetate in hexane as eluent to furnish the title compound (2.0 g).

¹ H NMR (CDCl ₃ , 300 MHz):δ 7.27(2H,d, 7.59Hz), 7.17 (3H,d, 7.62Hz), 5.71(lH,d, 3.12Hz), 5.44(lH,s), 4.62(lH,d, 3.4Hz), 3.72(8H,m), 3.57(2H,s), 3.36(3H,m), 1.99(1H, m), 1.78(2H,bs), 1.45(3H,s), 1.26(3H,s).

Analogues of l,2-O-Isopropylidene-3-deoxy-3-{2-[3-(4-{2-methoxy-2-oxoethy l}- ureido]-ethyl}-α-O-allofuranoside (Compound No. 26) can be prepared by using

appropriate sugar derivative in place of compound No. 4, respectively as applicable in each case.

l,2-O-Isopropylidene-3-O-[(4-methoxy-phenyl)-amino]-carbo nyl-α-D- allofuranoside (Compound No. 19)

l,2-O-Isopropylidene-3-deoxy-3-{2-[3-(4-methoxy-phenyl)-u reido]-ethyl}-α-D- glucofuranoside (Compound No. 20)

1 ,2-O-Isopropylidene-3-O- {(4-chloro-phenyl)-amino} -carbonyl-α-D- glucofuranoside (Compound No. 21)

l,2-O-Isopropylidene-3-deoxy-3-{[(4-nitro-phenyl)-amino]- carbonyl}-amino-α-D- allofuranoside (Compound No. 22)

l,2-O-Isopropylidene-3-deoxy-3-{[(4-chloro-phenyl)-amino] -carbonyl}-amino-α- D-allofuranoside (Compound No. 23)

1 ,2-O-Isopropylidene-3-O- {(4-methyl-phenyl)-amino} -carbonyl-α-D- glucofuranoside (Compound No. 24)

1 ,2-O-Isopropylidene-3 -deoxy-3 - [2- { 3 -(4-methyl-phenyl)-ureido } -ethyl] -oc-D- allofuranoside (Compound No. 25)

l,2-0-Isopropylidene-3-deoxy-3-{[(4-methyl-phenyl)-amino] -carbonyl}-amino-α- D-allofuranoside (Compound No. 27)

l,2-O-Isopropylidene-3-deoxy-3-{2-[3-(4-{2-hydroxy-2-oxo- ethyl}-phenyl)- ureido] -ethyl} -α-D-allofuranoside (Compound No. 28).

Scheme IX, (path a)

Example 16: Synthesis of l,2;5,6-Di-O-isopropylidene-3-deoxy-3-ir4-fluoro-phenyll- sulphonyl>-amino-α -D -allofuranoside (Compound No. 52)

To a solution of l,2;5,6-Di-O-isopropylidene-3-deoxy-3-amino-α-D-allofuranos ide (lOOmg) in dichloromethane (5ml), was added 4-fluorobenzenesulphonyl chloride (75mg)

at O ⁰ C and stirred the reaction mixture for 2 hours. Solvent was evaporated under reduced pressure. The reaction mixture was taken into water, extracted with ethyl acetate, and the combined organic extracts were washed with brine and dried over anhydrous sodium sulphate. Solvent was evaporated under reduced pressure and the residue thus obtained was purified with 40% ethyl acetate in hexane as eluent to furnish the title compound (77mg).

¹ H NMR (CDCl ₃ , 300 MHz):δ 7.92-7.97(2H,m), 7.23-7.18(3 H, m), 5.72(1 H, d, 3Hz), 5.15(1 H, d, 9Hz), 4.23-4.17(2 H, m), 3.98-3.95(2 H, m), 3.84-3.88(1 H, m), 3.56-3.20(1 H, m), 1.51(3H,s), 1.42(3 H, s), 1.32(3 H, s), 1.25(3 H, s).

Analogues of 1 ,2;5,6-Di-O-isopropylidene-3-deoxy-3- {[4-fluoro-phenyl]- sulphonyl}-amino-α-D-allofuranoside (compound no. 52) described below can be prepared by replacing appropriate sulphonyl group in place of 4-fluoro-benzenesulphonyl chloride , respectively, as applicable in each case.

l,2;5,6-Di-O-isopropylidene-3-deoxy-3-{[4-methyl-phenyl]- sulphonyl}-amino-cc-

D-allofuranoside (Compound No. 53).

Scheme IX, (path b)

Example 17: Synthesis of l,2;5,6-Di-O-isopropylidene-3-deoxy-3-{[(4-methoxy-2-oxo- ethyl)amino ^" |-carbonvU -methyl amino-α-D-allofuranoside (Compound No. 54)

To a solution of l,2;5,6-Di-0-isopropylidene-3-deoxy-3-amino-α-D-allofuranos ide (lOOmg) in dry acetone (10ml), at room temperature, was added potassium carbonate (172mg) followed by the addition of 4-(2-chloro-acetyl amino)-phenyl acetic acid methyl ester (lOOmg) after 5-10 minutes. The reaction mixture was stirred for 3 hours at room temperature followed by refluxing for overnight. Solvent was evaporated under reduced pressure .The reaction mixture was taken into water and extracted with ethyl acetate. The combined organic layer was washed with water, brine and dried over anhydrous sodium sulphate. The solvent was evaporated under reduced pressure and the residue thus obtained

was purified by column chromatography using 60% ethyl acetate in hexane to furnish the title compound (46 mg).

¹ H (CDCl ₃ , 300MHz): δ 9.61 (lH,s), 7.61 (2H,d, 9Hz), 7.26-7.22(4H,m), 5.77(1 H,s), 4.64(lH,d, 9Hz), 4.24-2.84(12H,m), 1.57(3 H, s), 1.46(3 H, s), 1.25(6H,s).

Pharmacological activity

The compounds of the present invention were tested in one or both of the assays described herein. Standard assays were used to evaluate activity of compounds in present invention on inflammatory cells. Attenuation of agonist-induced release of lipid mediator of neutrophil chemotaxis, leukotriene B4 (LTB4), was used to evaluate inhibitory effect on neutrophils.

A23187 induced LTB ₄ release

Venous blood was collected from healthy human donors using heparin as an anticoagulant. Neutrophils were isolated from freshly drawn blood after dextran sedimentation and ficoll separation {Eur J Biochem. 169, 175, 1987). 180 μl of the of neutrophil suspension (0.2xl0 ⁶ cells/ml) was taken and added 19μL of Hank's Buffer salt solution along with lμL of the test drug (200 times concentrated) in a 24 well plate and incubated at 37°C for Ihour. 3 minutes before the end of test compound incubation, 0.25 mM Ca ⁺ ^Mg ^+4" were added. Then, 0.3 μg/ml A23187 (Sigma Chem, USA) was added and incubated for further 10 min at 37°C. The reaction was stopped by adding 80 μL of cold methanol and centrifuged to remove cell debris (J Pharmacol Exp Ther. 297:267, 2001). The samples were analysed for LTB ₄ release using LTB ₄ ELISA kits (Assay Design Inc., USA). The amount of LTB ₄ released was quantified and percent inhibition of LTB ₄ release was calculated with respect to the difference between the A23187 stimulated and negative control cells, to compute IC5 ₀ values.

Compound Nos. 49, 50 and 52-54 were investigated and they exhibited IC50 of from about 30 μM to about 14 μM.

Assay for 5-Lipoxygenase Activity

In a 96 well UV-plate, 100 μl of phosphate buffer saline (PBS) containing DTT (200 μM), ATP (100 μM) and calcium chloride (100 μM) is added. To each well 0.5 μl of test drug (200 times concentrated) or vehicle is added, followed by 4 μl of recombinant 5- Lox (3 units/μl) and is incubated at 37°C for 5 min. The reaction was initiated by adding 1 μl of ImM freshly prepared arachidonic acid and increase in absorbance is monitored at 236 run for 10 min. (J Biol. Chem. 261:11512, 1986) A plot of absorbance verses time curve is prepared and area under curve (AUC) is computed for each well. Percent inhibition of AUC for different treatments is calculated with respect to the difference between the Arachidonic acid stimulated and negative control values, to compute IC50 values.