Details for Patent: 5,684,189

Title:	GABA and L-glutamic acid analogs for antiseizure treatment
Abstract:	A compound of the formula ##STR1## wherein R.sub.1 is a straight or branched alkyl group having from 1 to 6 carbon atoms, phenyl, or cycloalkyl having from 3 to 6 carbon atoms; R.sub.2 is hydrogen or methyl; and R.sub.3 is hydrogen, methyl or carboxyl; which is useful in the treatment of seizure disorders. Processes are disclosed for the preparation of the compound. Intermediates prepared during the synthesis of the compound are also disclosed.
Inventor(s):	Silverman; Richard B. (Morton Grove, IL), Andruszkiewicz; Ryszard (Sopot, PL), Yuen; Po-Wai (Ann Arbor, MI), Sobieray; Denis Martin (Holland, MI), Franklin; Lloyd Charles (Hamilton, MI), Schwindt; Mark Alan (Holland, MI)
Assignee:	Northwestern University (Evanston, IL) Warner-Lambert Company (Ann Arbor, MI)
Filing Date:	Apr 12, 1995
Application Number:	08/420,576
Claims:	1. A process for preparing an S-isomer of a compound of the formula which comprises hydrolyzing an azide of the formula ##STR9## to an intermediate azide of the formula ##STR10## extracting the intermediate carboxylic acid azide into an aqueous base and reducing the intermediate azide the to the amine of the formula ##STR11## wherein Bn is benzyl. 2. A process as defined in claim 1 wherein the azide is a benzyl ester and is hydrolysed by treatment with sodium hydroxide. 3. A process as defined in claim 1 further comprising the step of acidifying the aqueous extract. 4. A process as defined in claim 1 wherein the intermediate carboxylic acid azide is reduced under near neutral conditions to give the amino acid. 5. A process for preparing an S-isomer of a compound of the formula ##STR12## which comprises hydrolyzing an azide of the formula ##STR13## to an intermediate azide of the formula ##STR14## extracting the intermediate carboxylic acid azide into an aqueous base and reducing the intermediate azide the to the amine of the formula ##STR15## 6. A process as defined in claim 5 wherein the azide is a t-butyl ester and is hydrolysed by treatment with aqueous formic acid. 7. A process as defined in claim 5 further comprising the step of acidifying the aqueous extract. 8. A process as defined in claim 5 wherein the intermediate carboxylic acid azide is reduced under near neutral conditions to give the amino acid.