Sun Chemical Corporation

Terrence R Chamberlain

Russell J Schwartz

George H Robertson

Edward H Sung

Norman Wayne Smith

Donald Thomas DeRussy

George McLaren

Kathleen Marie Kozak

Barbara N Berg

Craig Thornley

A process for producing beta-phase quinacridone by (a) reacting 2,5-dianilino-terephthalic acid with polyphosphoric acid in the presence of 2,5-dianisidino-terephthalic acid at a reaction temperature of at least 85&deg; C.; (b) diluting the reaction mixture with water; (c) drowning the diluted mixture in a water-miscible alkanol; (d) heating the slurry at a temperature of from 100 to 130&deg; C. at a pressure of 20 to 50 psi; and (e) recovering the beta-phase quinacridone.

Process for the preparation of beta-phase quinacridone

A process for improving the heat stability of Pigment Violet 23 by conditioning crude Pigment Violet 23 in the presence of about 1 to 10 wt. % of Pigment Violet 23 by-products (1), (2) and (3).

Preparation of heat stable pigment violet 23

A synthesis for preparing asymmetrical 1,4-diketopyrrolo&lsqb;3,4-c&rsqb;pyrroles involving: (a) reacting a &bgr;-ketoamide with a strong base; (b) halogenating the same or a different &bgr;-ketoamide; (c) reacting the reaction products of step (a) and (b) to form a succinamide; and (d) heating the succinamide in the presence of a Lewis Acid. Symmetrical 1,4-diketopyrrolo &lsqb;3,4-c&rsqb;pyrroles are synthesized by oxidatively dimerizing the reaction product of step (b) to form a succinamide; and heating the succinamide in the presence of a Lewis Acid.

Syntheses for preparing 1,4-diketopyrrolo &lsqb;3,4-c&rsqb;pyrroles

A process for preparing 1,8-naphthalimide by reacting 1,8-naphthalic anhydride with ammonia in an aqueous solution under atmospheric pressure at 60 to 100&deg; C.

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Montgomery, OH, United States of America

Terrence R Chamberlain