Ranjit Kumar Roy

US Patent:

20030105350, Jun 5, 2003

Filed:

Dec 5, 2001

Appl. No.:

10/010404

Inventors:

Max Mortensen - Bend OR, US
Hassan Elnagar - Baton Rouge LA, US
Ranjit Roy - Baton Rouge LA, US
Robert Allen - Baton Rouge LA, US
David Caillet - Baton Rouge LA, US

International Classification:

C07C211/56
C07C069/76
C07C017/06

US Classification:

560/083000, 570/196000, 564/442000, 568/774000

Abstract:

A process for thermal benzylic bromination of a wide variety of benzylic compounds is described. Bromine is used as the bromination agent. Moderate temperatures are employed and the process can be used to produce in relatively pure form either mono- or dibrominated benzylic bromination products.

US Patent:

52909450, Mar 1, 1994

Filed:

Aug 11, 1992

Appl. No.:

7/925446

Inventors:

Ranjit K. Roy - Baton Rouge LA
Ali M. Dadgar - Baton Rouge LA
Donald O. Hutchinson - Baton Rouge LA
Keith G. Anderson - Baton Rouge LA

Assignee:

Ethyl Corporation - Richmond VA

International Classification:

C07D40306

US Classification:

548462

Abstract:

This invention relates to a process for preparing a white bisimide product which principally contains N,N'-alkylene-bis(tetrabromophthalimide) or N,N'-bis(tetrabromophthalimide). The process features: providing, in a reaction vessel, a solution containing tetrabromophthalic anhydride and a solvent which contains at least about 15 weight percent of a mono-, di- or tri- carboxylic acid having a dissociation constant not higher than 1. times. 10. sup. -3 at 25. degree. C. ; forming a reaction mass by adding to the solution a diamine or a diamine salt formed by the partial or total diamine neutralization of a mono-, di- or tri- carboxylic acid having a dissociation constant not higher than 1. times. 10. sup. -3 at 25. degree. C. , such formation of the reaction mass resulting in the production of a bisimide precipitate which becomes a constituent of the reaction mass; during the formation of the reaction mass, (i) retaining, in the reaction mass, at least a portion of the water produced during such formation, (ii) maintaining a substantially constant pressure in the reaction vessel, and (iii) not allowing the temperature of the reaction mass to reach a temperature below about 135. degree. C. ; terminating the addition of the diamine or diamine salt when the molar ratio of the tetrabromophthalic anhydride initially present in the solution to the diamine or diamine salt added is from about 1.

US Patent:

60969202, Aug 1, 2000

Filed:

Jul 8, 1998

Appl. No.:

9/111935

Inventors:

Robert H. Allen - Baton Rouge LA
R. Carl Herndon - Baton Rouge LA
Kannappan C. Chockalingam - Baton Rouge LA
W. Dirk Klobucar - Baton Rouge LA
Gary D. Focht - Baton Rouge LA
Tse-Chong Wu - Baton Rouge LA
Gary D. Heidebrecht - Orangeburg SC
Joseph D. McLean - Orangeburg SC
Yaping Zhong - Columbia SC
Thorsten W. Brockmann - Columbia SC
Ronny W. Lin - Baton Rouge LA
William J. Layman - Baton Rouge LA
Ranjit K. Roy - Baton Rouge LA

Assignee:

Albemarle Corporation - Richmond VA

International Classification:

C07C 5110

US Classification:

562406

Abstract:

Palladium-catalyzed arylation of an olefin (e. g. , ethylene) with an aromatic halide (e. g. , 2-bromo-6-methoxynaphthalene, m-bromobenzophenone, or 4-isobutyl-1-bromobenzene) is conducted in specified media. After a special acid or base phase separation procedure, palladium-catalyzed carbonylation of the olefinically-substituted aromatic intermediate is conducted in specified media using CO and water or an alcohol to form arylalkylcarboxylic acid or ester or substituted arylalkylcarboxylic acid or ester (e. g. , racemic 2-(6-methoxy-2-naphthyl)propionic acid, 2-(3-benzoylphenyl)propionic acid, or 2-(4-isobutylphenyl)propionic acid). Catalyst recovery procedures enabling recycle of catalyst residues and efficient recovery of amine hydrogen halide scavenger and solvent used in the arylation reaction are described, as well as novel, highly efficient methods of conducting the carbonylation reaction. The technology is economical and suitable for use on an industrial scale whereby reaction mixtures can be efficiently separated into the desired component mixtures without need for excessive capital investment or tedious, time-consuming operations. High yields of high purity products can be achieved.