Abstract: The present invention relates to an improved process for 4-(Hydroxymethyl)-5-methyl-1,3-dioxol-2-one (I). The process involves reaction of compound of formula (II) with sodium acetate in presence of catalytic amount of potassium iodide in dimethyl formamide solvent at 25-30° C. to give 5-methyl-2-oxo-1,3-dioxol-4-yl)methyl acetate (IV) which was further Acid hydrolysed by IPA.HCl in Isopropyl alcohol solvent to yield 4-(hydroxymethyl)-5-methyl-1,3-dioxol-2-one (I).

Abstract: The present invention provides an improved process for preparation of L-threo-(2S,3R)-3-(3,4-dihydroxyphenyl)serine (I) (Droxidopa) and its salts; comprising (a) reaction of the aldehyde compound (III) (as described herein) with Metal complex (II) (as described herein), and (h) hydrolysis of the compound (IV) obtained from step (a) in presence of acid. The present invention also relates to a novel intermediates metal chiral complex (IV) for the preparation of Droxidopa.

Abstract: The present invention provides an improved process for preparation of the L-threo-(2S,3R)-3-(3 4-dihydroxyphenyl)serine (I) or a salt thereof, which is known as Droxidopa; comprising (a) recovery of the by-product compound (V) (as described herein) from the crude compound (I), and (b) recycling and re-use it for the preparation of droxidopa. Accordingly, the present invention relates to an improved economical process for the preparation of L-threo-(2S,3R)-3-(3.4-dihydroxyphenyl)serine (I) or its pharmaceutically acceptable salts; wherein the process relates to recovery and recycling of the by-product compound (V) and also to re-use it for the preparation of droxidopa.

Abstract: The present invention provides an improved process for the preparation of 3-(4-chlorophenyl)-3-cyanopropanoic acid (compound (A)) and further its transformation to Baclofen (I). The process comprises reaction of compound (II) with Glyoxylic acid to obtain 3-(4-chlorophenyl)-3-cyanoacrylic acid (III); followed by the ‘in-situ’ reduction of (III) in the presence of a reducing agent to provide the compound (A). Alternatively, the compound (A) is obtained by the process comprising reacting 2-(4-chlorophenyl)acetonitrile (II) with haloacetic acid (IV) in the presence of a base. The compound 3-(4-chlorophenyl)-3-cyanopropanoic acid (A) undergoes hydrogenation in the presence of a metal catalyst and ammonia solution to provide Baclofen (I).

Abstract: The present invention provides an improved process for preparation of the L-threo-(2S,3R)-3-(3,4-dihydroxyphenyl)serine (I) or a salt thereof, which is known as Droxidopa; comprising (a) recovery of the by-product compound (V) (as described herein) from the crude compound (I), and (b) recycling and re-use it for the preparation of droxidopa. Accordingly, the present invention relates to an improved economical process for the preparation of L-threo-(2S,3R)-3-(3.4-dihydroxyphenyl)serine (I) or its pharmaceutically acceptable salts; wherein the process relates to recovery and recycling of the by-product compound (V) and also to re-use it for the preparation of droxidopa.

Abstract: The present invention provides an improved process for preparation of L-threo-(2S,3R)-3-(3,4-dihydroxyphenyl)serine (I) (Droxidopa) and its salts; comprising (a) reaction of the aldehyde compound (III) (as described herein) with Metal complex (II) (as described herein), and (h) hydrolysis of the compound (IV) obtained from step (a) in presence of acid. The present invention also relates to a novel intermediates metal chiral complex (IV) for the preparation of Droxidopa.

Abstract: The present invention relates to a novel process for the preparation of intermediate of fosaprepitant dimeglumine. The present invention particularly relates to a process for the preparation of fosaprepitant dibenzyl ester, an intermediate of fosaprepitant dimeglumine, which is simple, easy to handle on commercial scale and efficient.

Abstract: The present invention relates to a novel process for the preparation of intermediate of fosaprepitant dimeglumine. The present invention particularly relates to a process for the preparation of fosaprepitant dibenzyl ester, an intermediate of fosaprepitant dimeglumine, which is simple, easy to handle on commercial scale and efficient.

Abstract: The present invention provides an improved process for the preparation of 8-chloro-1-phenyl-1H-benzo[b][1,4]diazepine-2,4(3H,5H)-dione (hereafter referred to as the compound (IV)), which is useful as a key intermediate for the synthesis of Clobazam (referred to as the compound (I)) 7-chloro-1-methyl-5-phenyl-1H-benzo[b][1,4]diazepine-2,4(3H,5H)-dione. The process of the present invention further involves transformation of the compound (IV) into Clobazam (I), comprising (a) reacting the compound (II) (as described herein) with monoalkyl malonate in the presence of a coupling agent to obtain the compound (III) (as described herein); followed by the cyclization using a base; (b) reacting the compound-IV (as described herein) obtained from step (a) with methylating agent. The process of the present invention involves formation of novel intermediates methyl 3-((4-chloro-2-(phenylamino)phenyl)amino)-3-oxopropanoate (IIIa) and 3-((4-chloro-2-(phenylamino)phenyl)amino)-3-oxopropanoic acid (V).

Abstract: The present invention provides an improved process for the preparation of 3-(4-chlorophenyl)-3-cyanopropanoic acid (compound (A)) and further its transformation to Baclofen (I). The process comprises reaction of compound (II) with Glyoxylic acid to obtain 3-(4-chlorophenyl)-3-cyanoacrylic acid (III); followed by the ‘in-situ’ reduction of (III) in the presence of a reducing agent to provide the compound (A). Alternatively, the compound (A) is obtained by the process comprising reacting 2-(4-chlorophenyl)acetonitrile (II) with haloacetic acid (IV) in the presence of a base. The compound 3-(4-chlorophenyl)-3-cyanopropanoic acid (A) undergoes hydrogenation in the presence of a metal catalyst and ammonia solution to provide Baclofen (I).

Abstract: The present invention provides an improved process for the preparation of 8-chloro-1-phenyl-1H-benzo[b][1,4]diazepine-2,4(3H,5H)-dione (hereafter referred to as the compound (IV)), which is useful as a key intermediate for the synthesis of Clobazam (referred to as the compound (I)) 7-chloro-1-methyl-5-phenyl-1H-benzo[b][1,4]diazepine-2,4(3H,5H)-dione. The process of the present invention further involves transformation of the compound (IV) into Clobazam (I), comprising (a) reacting the compound (II) (as described herein) with monoalkyl malonate in the presence of a coupling agent to obtain the compound (III) (as described herein); followed by the cyclization using a base; (b) reacting the compound-IV (as described herein) obtained from step (a) with methylating agent. The process of the present invention involves formation of novel intermediates methyl 3-((4-chloro-2-(phenylamino) phenyl)amino)-3-oxopropanoate (IIIa) and 3-((4-chloro-2-(phenylamino)phenyl)amino)-3-oxopropanoic acid (V).

Abstract: The present invention provides a process for the preparation of 5-[[(2R,3S)-2-[(1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethoxy]-3-(4-fluorophenyl)-4-morpholinyl]methyl]-1,2-dihydro-3H-1,2,4-triazole-3-one (Aprepitant) comprising condensation of 2-(R)-[(1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethoxy]-3-(S)-(4-fluorophenyl)morpholine hydrochloride salt with 2-(2-chloro-1-iminoethyl)hydrazinecarboxylic acid methyl ester to obtain the reaction mixture containing 2-[2-[(2R,3S)-2-[(1R)-1-[3,5-bis(trifluoromethyl)phenyl]ethoxy]-3-(4-fluorophenyl)-4-morpholinyl]-1-iminoethyl]hydrazinecarboxylic acid methyl ester, which is in-situ cyclized in the presence of dimethylsulfoxide and a polar protic solvent at a low temperature to yield aprepitant having purity ?99.5%.

Abstract: The present invention relates to an improved process for the preparation Of (2S,3aS,7aS)-1-[(2S)-2-[[(1S)-1-(ethoxycarbonyl)butyl]amino]3-S-oxopropyl]octahydro-1H-indole-2-carboxylic acid benzyl ester (the compound of formula II) comprising reacting (2S,3aS,7aS)-octahydro-1H-indole-2-carboxylic acid phenylmethyl ester 4-methylbenzenesulfonate (the compound of formula III) with N-[(S)-ethoxycarbonyl-1-butyl]-(S)-alanine (the compound of formula IV), using 1-hydroxybenzotriazole (HOBT), dicyclohexylcarbodimide (DCC) and triethylamine in the presence of toluene as a solvent at a temperature of 5-40° C.

Abstract: The present invention relates to an improved process for the preparation of 1,3,5-triazine-2,4,6(1H,3H,5H)-trione (“Triglycidylisocyanurate (TGIC) or the compound of formula I”) comprising reacting cyanuric acid (the compound of formula III) with 3 to 7 molar equivalents of epichlorohydrin in an autoclave at a temperature of 80-100° C. for 1 hour to give the mixture of intermediates A, B and C and reacting intermediates A, B and C with an alkali to obtain the compound of formula I.

Abstract: The present invention provides a process for the preparation of 2-[(2-amino-1,6-dihydro-6-oxo-9H-yl)]ethyl L-valine ester hydrochloride (valacyclovir hydrochloride) of formula I comprising deprotection of N-[(benzyloxy)carbonyl]-L-valine-2-[(2-amino-1,6-dihydro-6-oxo-9H-purin-9-yl)methoxy]ethyl ester, of formula II using 5% palladium on carbon as a catalyst and mineral acid in the presence of water, avoiding use of organic solvents under hydrogen pressure to yield valacyclovir hydrochloride having yield of ?90% and purity of ?99.5%, pharmaceutically acceptable grade. The valacyclovir hydrochloride obtained using the process of the present invention is valacyclovir hydrochloride polymorphic Form I.

Abstract: The present invention provides a process for the preparation of key intermediate for the synthesis 5,6-dimethoxy-2-[[1-(phenylmethyl)-4-piperidinyl]methyl]-1-indanone hydrochloride (donepezil hydrochloride). The present invention particularly provides a process for the preparation of 5,6-dimethoxy-2-(4-pyridylmethylene)-1-indanone comprising condensation of 5,6-dimethoxy-1-indanone with 4-pyridinecarboxaldehyde using an alkali metal hydroxide as a mild base in the presence of demineralized water as a solvent at a temperature in the range of 15° C. to 45° C. to yield 5,6-dimethoxy-2-(4-pyridylmethylene)-1-indanone, which is subsequently benzylated using benzyl bromide in the presence of solvent at a reflux temperature to yield 1-benzyl-4-[(5,6-dimethoxy-1-indanone-2-yl)methylene]pyridinium bromide.