Warner-lambert Company

Thomas Mulhern

Denis Martin Sobieray

Robert D Titus

Brian Keith Huckabee

Todd Michel Grote

Om Prakash Goel

Thomas F Mich

James Andrew Ramsden

Marvin Simon Hoekstra

Mark Joseph Burk

This invention provides a method of making (S)-(+)-3-(aminomethyl)-5-methylhexanoic acid (pregabalin) or a salt thereof via an asymmetric hydrogenation synthesis. Pregabalin is useful for the treatment and prevention of seizure disorders, pain, and psychotic disorders. The invention also provides intermediates useful in the production of pregabalin.

Asymmetric synthesis of pregabalin

A method of making (.+-.)-3-(aminomethyl)-5-methylhexanoic acid that comprises condensing isovaleraldehyde with ##STR1## to form primarily ##STR2## reacting the ##STR3## with a cyanide source to form ##STR4## decarboxylating the ##STR5## to form ##STR6## hydrolyzing the ##STR7## with an alkali or alkaline earth metal hydroxide to form an alkali or alkaline earth metal carboxylate salt; and hydrogenating the alkali or alkaline earth metal carboxylate salt to form (.+-.)-3-(aminomethyl)-5-methylhexanoic acid, wherein R.sub.1 and R.sub.2 are the same or different and are hydrogen, C.sub.1 -C.sub.6 alkyl, aryl, benzyl, or C.sub.3 -C.sub.6 cycloalkyl. The present invention also provides a method of making (.+-.)-3-(aminomethyl)-5-methylhexanoic acid that comprises condensing isovaleraldehyde with ##STR8## to form primarily ##STR9## reacting the ##STR10## with a cyanide source to form ##STR11## decarboxylating the ##STR12## to form an alkali or alkaline earth metal carboxylate salt; and hydrogenating the alkali or alkaline earth metal carboxylate salt to form (.+-.)-3-(aminomethyl)-5-methylhexanoic acid.

Method of making (S)-3-(aminomethyl)-5-methylhexanoic acid

Method of making (S)-3-(Aminomethyl)-5-Methylhexanoic acid

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Hudsonville, MI, United States of America

Thomas Mulhern