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Kesireddy Subash Chander Reddy, Hyderabad IN

Kesireddy Subash Chander Reddy, Hyderabad IN

Patent application numberDescriptionPublished
20080293938Novel Process for the Preparation of Didanosine Using Novel Intermediates - 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.11-27-2008
20090054682 PROCESS FOR OSELTAMIVIR PHOSPHATE - The present invention provides an improved and commercially viable process for the preparation of oseltamivir phosphate. Thus, for example, ethyl (3R,4R,5S)-4-amino-5-azido-3-(1-ethylpropoxy)-1-cyclohexene-1-carboxylate is acetylated with acetic anhydride in methylene chloride in the presence of triethyl amine in the absence of water to give ethyl (3R,4R,5S)-4-(acetylamino)-5-azido-3-(1-ethylpropoxy)-1-cyclohexene-1-carboxylate.02-26-2009
20090149670PROCESS FOR OBTAINING PURE OSELTAMIVIR - 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.06-11-2009
20090177009PROCESS OF MAKING SERTRALINE FORM II - 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.07-09-2009
20090177010PROCESS OF MAKING SERTRALINE FORM I - 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.07-09-2009
20090197907NOVEL CRYSTALLINE FORM OF RUPATADINE FREE BASE - The present invention relates to a novel crystalline form of rupatadine free base, process for its preparation and to a pharmaceutical composition containing it. In accordance with the present invention rupatadine is suspended in n-hexane, n-heptane, cyclohexane, diethyl ether or diisopropyl ether, stirred for at least 1 hour, filtered the solid and dried to give crystalline rupatadine form-B. The isolation of novel rupatadine free base as crystalline form-B may be useful as a purification of rupatadine or a salt thereof.08-06-2009
20100076022NOVEL POLYMORPHS OF RIMONABANT - The present invention discloses novel and stable polymorphs of rimonabant, its hydrates and solvates, to the processes for their preparation and to pharmaceutical compositions comprising them. The present invention further discloses a novel and stable amorphous form of rimonabant, process for its preparation and a pharmaceutical composition comprising it. The present invention also provides an improved process for the preparation of rimonabant crystalline Form II. Thus, for example, rimonabant is dissolved in methylene dichloride, stirred for 10 minutes at 25-30° C. and then the solvent distilled off under vacuum at 40° C. The resulting residue is stirred with water and the separated solid is collected at 25-30° C. to give a stable crystalline rimonabant hydrate.03-25-2010
20100076197PROCESS FOR RIMONABANT - The present invention provides an improved and commercially viable process for the preparation of rimonabant substantially free of amide impurity, namely 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl-4-methyl-pyrazole-3-carboxamide and its pharmaceutically acceptable acid addition salts thereof. Thus, for example, 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl-4-methyl-pyrazole-3-carboxylic acid chloride is reacted with 1-aminopiperidine in the presence of a base and optionally a phase transfer catalyst is used such as tetra-butylammonium bromide in a biphasic reaction medium containing water and a water-immiscible solvent to obtain pure rimonabant.03-25-2010
20100137632PROCESS FOR OSELTAMIVIR PHOSPHATE - The present invention provides an improved and commercially viable process for the preparation of oseltamivir phosphate. Thus, for example, ethyl (3R,4R,5S)-4-amino-5-azido-3-(1-ethylpropoxy)-1-cyclohexene-1-carboxylate is acetylated with acetic anhydride in methylene chloride in the presence of triethyl amine in the absence of water to give ethyl (3R,4R,5S)-4-(acetylamino)-5-azido-3-(1-ethylpropoxy)-1-cyclohexene-1-carboxylate.06-03-2010
20100210868PROCESS FOR OBTAINING PURE OSELTAMIVIR - 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.08-19-2010
20110137034PROCESS FOR PREPARING LAMIVUDINE POLYMORPH FORM - The invention relates to a process for the preparation of stable lamivudine polymorph form and to a composition comprising thereof.06-09-2011

Patent applications by Kesireddy Subash Chander Reddy, Hyderabad IN