Hoechst Celanese Corporation

B Frank Wood

Ahmed M Tafesh

Graham N Mott

Joseph A McDonough

Olan S Fruchey

Charles B Hilton

Edward G Zey

Carrie A Feeney

Bennett C Ward

Thomas M Kenesson

Thomas H Shockley

Daniel D Lindley

Edward M De La Garza

Michael R Ahern

Thomas L Grantland

Gregory M Adams

Ida L Jones

Joe S Trevino

James L Ragan

Kan J Tsai

Processes for recovering 4,4'-dimethyl bibenzoate (DMBB) from byproduct streams of dimethyl terephthalate (DMT) production are disclosed. The byproduct streams are treated to produce an overhead stream which includes DMBB. In one aspect of the invention, the overhead product stream is added to an organic solvent under conditions sufficient to rapidly form a suspension of crystallized DMBB. In another aspect of the invention, the overhead is dissolved in an appropriate organic solvent and cooled to form a suspension of DMBB crystals in the solvent. A portion of the suspension is removed, and the remaining portion of the suspension centrifuged to recover DMBB crystals. In still another aspect of the invention, the overhead stream is treated with an organic solvent to form a slurry of DMBB crystals, and the resultant slurry thermally treated to increase the concentration of DMBB crystals therein while also solubilizing any organic contaminants.

Processes for cystallizing 4, 4'-dimethyl bibenzoate (DMBB) recovered

A method is provided for purifying crude N-acetyl-para-aminophenol (APAP) containing color bodies or their precursors, the method comprising: a) forming a solution of the crude APAP; and b) subsequently contacting the solution with substoichiometric quantifies of an acetylating agent for a sufficient period of time to convert said color bodies or their precursors to substantially non-color bodies/stable, colorless substances; said quantities of acetylating agent provided is such that substantially none of the APAP is converted to other compounds.

Color control & stability in acetaminophen

This invention provides a process for directly preparing arylethylamines and their salts from (.alpha.-halo-.alpha.-oximino)acetophenones. The process involves hydrogenation in presence of a transition metal catalyst. The process is illustrated by conversion of 4-hydroxy-(.alpha.-chloro-.alpha.-oximino)acetophenone to Tyramine hydrochloride: ##STR1##

Process for the preparation of arylethylamines and substituted

This invention provides a process for directly preparing hydrohalide salts of arylethylamines from (.alpha.-chloro-.alpha.-oximino)acetophenones. The process involves hydrogenation in presence of a transition metal catalyst in an organic acid in substantial absence of moisture. The process is illustrated by conversion of 4-hydroxy (.alpha.-chloro-.alpha.-oximino)acetophenone to Tyramine hydrochloride: ##STR1##

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Corpus Christi, TX, United States of America

B Frank Wood