Abstract: The present invention provides a novel process for the preparation of gemifloxacin and its pharmaceutically acceptable acid addition salts in high yield. The present invention also relates to novel polymorphs of gemifloxacin free base and its hydrates to the processes for their preparation and to pharmaceutical compositions comprising them. The present invention also relates to infusion solutions of gemifloxacin and to processes for their preparation. Thus, 7-chloro-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro-1,8-naphth-yridine-3-carboxylic acid is reacted with a mixture of acetic anhydride, acetic acid and boric acid to give borane compound, which is then treated with 4-Aminomethyl-3-methoxyimino-pyrrolidinium dimethanesulfonate in presence of triethylamine, followed by treatment with 3.5% sodium hydroxide solution to give gemifloxacin free base.

Abstract: The present invention provides an improved and commercially viable process for preparation of substantially enantiomerically pure esomeprazole in neutral form or as a pharmaceutically acceptable salt or as its solvates including hydrates. Thus, for example, a compound containing a mixture of 1-(S)-camphorsulfonyl-5-methoxy-2-[(3,5-dimethyl-4-methoxy-2-pyridyl)methyl-(S)-sulfinyl]-1H-benzimidazole and 1-(S)-camphorsulfonyl-6-methoxy-2-[(3,5-dimethyl-4-methoxy-2-pyridyl)methyl-(S)-sulfinyl]-1H-benzimidazole is hydrolyzed with barium hydroxide, isolated the resulting esomeprazole barium salt followed by neutralization with an acid to yield substantially enantiomerically pure esomeprazole in neutral form and then converted into its pharmaceutically acceptable salts.

Abstract: The present invention relates to a process for stereo selective synthesis of substituted sulfoxides either as a single enantiomer or in an enantiomerically enriched form. Thus, 5-methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl) methyl]thio]-1H-benzimidazole is reacted with (R)-camphorsulfonyl chloride to form a mixture of 1-(R)-camphorsulfonyl-5- (and 6-)methoxy-2-[(3,5-dimethyl-4-methoxy -2-pyridyl)methylthio]-1H-benzimidazole, oxidized to obtain a diastereomeric excess of 1-(R)-camphorsulfonyl-(5- and 6-)-methoxy-2-[(3,5-dimethyl -4-methoxy-2-pyridyl)methyl-(S)-sulfinyl]-1H-benzimidazole over 1-(R)-camphorsulfonyl -(5- and 6-)-methoxy-2-[(3,5-dimethyl-4-methoxy-2-pyridyl) methyl-(R)-sulfinyl]-1H-benzimidazole, the diastereomers are separated by fractional crystallization and the separated 1-(R)-camphorsulfonyl-(5- and 6-)-methoxy -2-[(3,5-dimethyl-4-methoxy-2-pyridyl)methyl-(S)-sulfinyl]-1H-benzimidazole is deprotected to give esomeprazole.

Abstract: The present invention provides an improved process for preparation of (E)-?-[[2-butyl-1-[[4-(methoxycarbonyl)phenyl]methyl]-1H-imidazole-5-yl]methylene]-2-thiophene propanoic acid ethyl ester in high purity and in high yield. Thus, for example, 4-[[2-butyl-5-formyl-1H-imidazole-1-yl]methyl]benzoic acid methyl ester is reacted with ethyl 2-carboxy-3-(2-thienyl)propionate in the presence of piperidinium propionate in diisopropyl ether or a mixture of n-hexane and a solvent selected from toluene and cyclohexane, optionally purifying the crude compound to obtain (E)-?-[[2-butyl-1-[[4-(methoxy carbonyl)phenyl]methyl]-1H-imidazole-5-yl]methylene]-2-thiophene propanoic acid ethyl ester substantially free of 3-(2-thienyl)propanoic acid ethyl ester impurity.

Abstract: The present invention relates to a simple and commercially viable process for separation of desired isomers of nebivolol intermediates from a mixture containing undesired isomers of nebivolol intermediates. Thus, (+)-[2R*[1S*,5S*(S*)]]+[2R*[1S*,5R*(R*)]]-?,??-[phenylmethyliminobis(methylene)]bis[6-fluoro-3,4-dihydro-2H-1-benzopyran-2-methanol] is dissolved in diisopropyl ether at reflux temperature and cooled to below about 30° C. to obtain the desired (+)-[2R*[1S*,5S*(S*)]]-?,??-[phenylmethyliminobis(methylene)]bis[6-fluoro-3,4-dihydro-2H-1-benzopyran-2-methanol].

Abstract: The present invention provides a novel process for the preparation of gemifloxacin and its pharmaceutically acceptable acid addition salts in high yield. The present invention also relates to novel polymorphs of gemifloxacin free base and its hydrates to the processes for their preparation and to pharmaceutical compositions comprising them. The present invention also relates to infusion solutions of gemifloxacin and to processes for their preparation. Thus, 7-chloro-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro-1, 8-naphthyridine-3-carboxylic acid is reacted with a mixture of acetic anhydride, acetic acid and boric acid to give borane compound, which is then treated with 4-Aminomethyl-3-methoxyimino-pyrrolidinium dimethanesulfonate in presence of triethylamine, followed by treatment with 3.5% sodium hydroxide solution to give gemifloxacin free base.

Abstract: The present invention provides an improved and commercially viable process for preparation of irbesartan intermediate, 1-[(2?-cyanobiphenyl-4-yl)methyl]-2-n-butyl-4-spirocyclopentane-2-imidazolin-5-one, substantially free of 1-[(2?-cyanobiphenyl-4-yl)methyl]-2-n-propyl-4-spirocyclopentane-2-imidazolin-5-one impurity, thereby producing irbesartan substantially free of the undesired propyl analog impurity, namely 2-propyl-3-[[2?-(1H-tetrazol-5-yl)[1,1?-biphenyl]-4-yl]methyl]-1,3 -diazaspiro[4.4]non-1-en-4-one. The present invention also provides a process for preparation of irbesartan substantially free of tin content. The present invention further provides a commercially viable process for preparation of irbesartan in high purity and in high yield.

Abstract: The present invention relates to a high assayed esomeprazole magnesium dihydrate substantially free of its trihydrate form. The present invention further provides an improved and commercially viable process for preparation of high assayed esomeprazole magnesium dihydrate substantially free of its trihydrate form. The present invention also provides an improved process for preparation of pure amorphous esomeprazole magnesium. The present invention further provides an improved and commercially viable process for preparation of substantially enantiomerically pure esomeprazole in neutral form or as a pharmaceutically acceptable salt or as its solvates including hydrates. The present invention also provides solid form of esomeprazole calcium salt, its polymorphs (form 1, form 2 and amorphous form) and processes for their preparation thereof.

Abstract: There was provided a process for preparing candesartan cilexetil, the said process comprises hydrogenating a solution of trityl candesartan cilexetil in an alcohol with hydrogen in the presence of a palladium catalyst. Mixture of toluene and methanol was added to 1-(Cyclohexyloxy carbonyloxy)ethyl-2-ethoxy-1-[[2?-(N-triphenylmethyltetrazole-5-yl)biphenyl-4-yl]methyl]benzimidazole-7-carboxylate and hydrogenated at room temperature with hydrogen at atmospheric pressure in the presence of palladium on carbon until the hydrogen uptake was ceased. Filtered over celite bed, washed the bed with a mixture of toluene and methanol, filtrate was collected and concentrated. Co-distilled with acetonitrile, acetonitrile was added, stirred at room temperature, cooled to 0° C. stirred, filtered, washed with chilled acetonitrile and dried to get candesartan cilexetil.

Abstract: The present invention provides a process for obtaining highly pure crystalline form of oseltamivir free base, thus, for example, suspending or dissolving impure or non-crystalline oseltamivir free base in a hydrocarbon solvent and then isolating crystals to obtain oseltamivir free base in well defined crystalline form. The present invention also provides a process for preparation of oseltamivir phosphate in high purity.

Abstract: The present invention provides an improved and efficient process for the preparation of highly pure amorphous rabeprazole sodium. Thus, for example, rabeprazole is dissolved in an alcoholic sodium hydroxide solution followed by carbon treatment, the resulting filtrate is distilled under vacuum at 50-52° C. followed by co-distillation with cyclohexane and the resulting residue is dissolved in anisole; the solution is added to cyclohexane under agitation and then the precipitated solid collected by filtration or centrifugation.

Abstract: The present invention discloses novel and improved processes for preparation of sertraline hydrochloride crystalline form II. Thus, for example, sertraline free base is dissolved in isoamyl alcohol at 25-30° C., pH of the mass is adjusted to 2.0 with conc. hydrochloric acid (36%) at 25-30° C. and then stirred for 14 hours at 25-30° C. Filtered the solid and dried at 65° C. for 4 hours to give sertraline hydrochloride crystalline form II. The present invention also provides a novel process for preparation of sertraline hydrochloride crystalline form I.

Abstract: The present invention discloses novel and improved processes for preparation of sertraline hydrochloride crystalline form II. Thus, for example, sertraline free base is dissolved in isoamyl alcohol at 25-30° C., pH of the mass is adjusted to 2.0 with conc. hydrochloric acid (36%) at 25-30° C. and then stirred for 14 hours at 25-30° C. Filtered the solid and dried at 65° C. for 4 hours to give sertraline hydrochloride crystalline form II. The present invention also provides a novel process for preparation of sertraline hydrochloride crystalline form I.

Abstract: The present invention provides a novel process for the preparation of amorphous form of donepezil hydrochloride.

Abstract: The invention provides a novel process for the preparation of lercanidipine or a pharmaceutical acceptable salt using novel intermediates. Thus, 2,N-dimethyl-N-(3,3-diphenylpropy1)-1-amino-2-propanol is reacted with trimethylsilyl chloride in presence of triethyl amine in methylene chloride to give 2,N-dimethyl-2-(trimethylsilyloxy)-N-(3,3-diphenylpropy1)-1-propanamine, which is then reacted with 2,6-dimethyl-5-methoxycarbonyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3-carbonyl chloride for 2 hours and crystallized to obtain lercanidipine hydrochloride.

Abstract: The present invention provides a novel process for the preparation of the prulifloxacin intermediate, 6-fluoro-1-methyl-4-oxo-7-(1-piperazinyl)-4H-[1,3] thiazeto[3,2-a]quinoline-3-carboxylic acid, thereby producing prulifloxacin and its pharmaceutical acceptable acid addition salts thereof in high purity and in high yield using novel intermediates in lesser reaction time. Thus, for example, ethyl 6,7-difluoro-1-methyl-4-oxo-4H-[1,3]thiazeto[3,2-a]quinoline-3-carboxylate is reacted with boric acid in the presence of acetic anhydride and acetic acid to give a borane compound, which is then condensed with piperazine in the presence of acetonitrile and dimethylsulfoxide, followed by treatment with potassium hydroxide solution to give 6-fluoro-1-methyl-4-oxo-7-(1-piperazinyl)-4H-[1,3] thiazeto [3,2-a]quinoline-3-carboxylic acid.

Abstract: The present invention provides an improved and commercially viable process for preparation of substantially enantiomerically pure esomeprazole in neutral form or as a pharmaceutically acceptable salt or as its solvates including hydrates. Thus, for example, a compound containing a mixture of 1-(S)-camphorsulfonyl-5-methoxy-2-[(3,5-dimethyl-4-methoxy-2-pyridyl)methyl-(S)-sulfinyl]-1H-benzimidazole and 1-(S)-camphorsulfonyl-6-methoxy-2-[(3,5-dimethyl-4-methoxy-2-pyridyl)methyl-(S)-sulfinyl]-1H-benzimidazole is hydrolyzed with barium hydroxide, isolated the resulting esomeprazole barium salt followed by neutralization with an acid to yield substantially enantiomerically pure esomeprazole in neutral form and then converted into its pharmaceutically acceptable salts.

Abstract: The present invention relates to novel crystalline alkali metal and alkaline earth metal salts of 2?,3?-dideoxy-2?,3?-didehydroinosine. The present invention also provides a novel process for preparation of didanosine in high yield and purity using novel intermediates. Thus, for example, 5?-O-acetyl-2?,3?-dideoxy-2?,3?-didehydroinosine is reacted with monomethyl amine to give 2?,3?-dideoxy-2?,3?-didehydro inosine, which is then reacted with sodium hydroxide and crystallized to give crystalline 2?,3?-dideoxy-2?,3?-didehydroinosine sodium salt. 2?,3?-Dideoxy-2?,3?-didehydroinosine sodium salt is hydrogenated using raney nickel catalyst in aqueous medium and then neutralized with hydrochloric acid to yield didanosine.

Abstract: The present invention relates to eprosartan mesylate particles having relatively larger surface area, to the methods for the manufacture of said crystalline particles, and to pharmaceutical compositions comprising said crystalline particles. The present invention further relates to crystalline solid of eprosartan acetate, to a process for its preparation and to a pharmaceutical composition comprising it. The present invention also provides substantially pure eprosartan free base and process for its preparation.

Abstract: The present invention relates to two novel and stable crystalline forms of atovaquone, to processes for their preparation and to pharmaceutical compositions comprising them. The present invention also provides crystalline particles of atovaquone having a specific surface area of from about 0.7 m2/g to about 4 m2/g, methods for the manufacture of said crystalline particles and pharmaceutical compositions comprising said crystalline particles. The present invention further provides an improved and commercially viable process for preparation of atovaquone substantially free of its undesired isomeric impurity, namely cis-2-[4-(4-chlorophenyl)cyclohexyl]-3-hydroxy-1,4-naphthoquinone.