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 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 novel intermediate of ethyl 6-[2-(4,4-dimethylthiochroman-6-yl)ethynyl] nicotinate or a pharmaceutically acceptable salt thereof and a process for its preparation. The present invention also provides for the preparation of ethyl 6-[2-(4,4-dimethylthiochroman-6-yl)ethynyl] nicotinate of Formula I or a pharmaceutically acceptable salt thereof using the intermediate.

Abstract: A process for preparing neutral esomeprazole in an amorphous form is provided comprising (a) providing an aqueous solution comprising a salt of esomeprazole; (b) neutralizing the solution with a neutralization agent to provide a neutralized solution; (c) contacting the neutralized solution with an extracting solvent; and (d) recovering the neutral esomeprazole in an amorphous form.

Abstract: A process for preparing Form II crystals of clarithromycin is provided comprising (a) treating clarithromycin with a carboxylic acid in an organic solvent to provide a clarithromycin acid salt; and, (b) heating the clarithromycin acid salt at a temperature capable of providing Form II crystals of clarithromycin.

Abstract: A process for the preparation of a disubstituted acetylene bearing heteroaromatic and heterobicyclic groups of formula I is provided wherein X is S, O, or NR1 wherein R1 is hydrogen or a C1-C6 straight or branched alkyl group; R is hydrogen or a C1-C6 straight or branched alkyl group; A is a substituted or unsubstituted pyridinyl, thienyl, furyl, pyridazinyl, pyrimidinyl or pyrazinyl group; n is 0-4; and B is H, —COOH, —CH2OH, —CHO or a C1-C6 alkyl acetal derivative, —COR2 or a C1-C6 alkyl ketal derivative where R2 is —(CH2)mCH3 where m is 0-4 or COOR3 wherein R3 is a straight or branched C1-C30 alkyl group, a substituted or unsubstituted C6-C30 aromatic group, a substituted or unsubstituted C3-C30 cycloalkyl, a substituted or unsubstituted C3-C30 cycloalkylalkyl, a substituted or unsubstituted C3-C30 cycloalkenyl, a substituted or unsubstituted C5-C30 aryl, a substituted or unsubstituted C5-C30 arylalkyl, a substituted or unsubstituted C5-C30 heteroaryl, a substituted or unsubstituted C3-C30 heterocycli

Abstract: An improved process for the preparation of key intermediates for tazarotene, 4,4-dimethyl-6-ethynylthiochroman, is provided comprising (a) reacting 4,4-dimethyl-6-acetylthiochroman of the formula with an acid chloride and an amido-group containing compound of the general formula wherein R is hydrogen or a hydrocarbyl of from 1 to 15 carbon atoms and R1 and R2 can be the same or different and are hydrocarbyls of from 1 to 15 carbon atoms or R1 and R2 together with the nitrogen atom to which they are bonded are joined together to form a heterocyclic group, optionally containing one or more additional heterocyclic atoms, or one of R1 and R2 together with the nitrogen atom to which it bonded are joined together with the carbonyl radical to form a heterocyclic group, optionally containing one or more additional heterocyclic atoms to form a chloro vinyl carbonyl compound intermediate of the general formula wherein R has the aforestated meanings; and (b) reacting the ?-chloro vinyl carbonyl compound inte

Abstract: An improved process for the preparation of key intermediates for tazarotene, 4,4-dimethyl-6-ethynylthiochroman, is provided comprising (a) reacting 4,4-dimethyl-6-acetylthiochroman of the formula with an acid chloride and an amido-group containing compound of the general formula wherein R is hydrogen or a hydrocarbyl of from 1 to 15 carbon atoms and R1 and R2 can be the same or different and are hydrocarbyls of from 1 to 15 carbon atoms or R1 and R2 together with the nitrogen atom to which they are bonded are joined together to form a heterocyclic group, optionally containing one or more additional heterocyclic atoms, or one of R1 and R2 together with the nitrogen atom to which it bonded are joined together with the carbonyl radical to form a heterocyclic group, optionally containing one or more additional heterocyclic atoms to form a ?-chloro vinyl carbonyl compound intermediate of the general formula wherein R has the aforestated meanings; and (b) reacting the ?-chloro vinyl carbonyl compound in