Alicia D W Potter

US Patent:

53027515, Apr 12, 1994

Filed:

Jan 21, 1992

Appl. No.:

7/823367

Inventors:

Thanikavelu Manimaran - Baton Rouge LA
Alicia A. Potter - Baton Rouge LA

Assignee:

Ethyl Corporation - Richmond VA

International Classification:

C07B 5700
C07D30702
C07C 6760

US Classification:

562401

Abstract:

A process is disclosed that is useful for separating the enantiomers of a racemic mixture of an aliphatic carboxylic acid having the formula ##STR1## where R. sub. 1 is hydrogen or alkyl, R. sub. 2, R. sub. 3 and R. sub. 4 are independently different and are hydrogen, alkyl, cycloalkyl, alkenyl, alkynyl, phenyl, substituted phenyl, naphthyl, substituted naphthyl, heteroaryl, substituted heteroaryl, haloalkyl, alkoxyalkyl, alkylthioalkyl, phenylalkyl, substituted phenylalkyl, heteroalkylalkyl, substituted heteroalkylalkyl or cycloalkylalkyl. The process comprises forming a conglomerate salt by reacting the racemic mixture with a base, the conglomerate salt being a mixture of the enantiomeric salts and having the following properties: i) the infrared spectrum of each of the enantiomeric salts, individually, and of the racemate salt are superposable; ii) the melting point of each of the enantiomeric salts, individually, is greater than the melting point of the racemate salt; and iii) the solubility of each of the enantiomeric salts, individually, is less than the solubility of the racemate salt in the same solvent. The enantiomeric salts are readily separable from the racemic mixture.

US Patent:

51625768, Nov 10, 1992

Filed:

Apr 15, 1991

Appl. No.:

7/684809

Inventors:

Thanikavelu Manimaran - Baton Rouge LA
Alicia A. Potter - Baton Rouge LA

Assignee:

Ethyl Corporation - Richmond VA

International Classification:

C07B 5700

US Classification:

562401

Abstract:

A method for resolving (. +-. )-(. alpha. )-(3-benzoylphenyl) propionic acid is disclosed. The method comprises: i) converting said propionic acid with (-)-cinchonidine in a solvent comprising a mixture of an aliphatic ester and an alkyl alcohol; ii) separating teh diastereomeric salt from such conversion; iii) purifying said separated diastereomeric salt by a single recrystallization; and iv) isolating highly pure (+)-. alpha. -(3-benzoylphenyl) propionic acid without any further recrystallization.