Bayer Aktiengesellschaft

Rupert Wenzel

Gerhard Scharfe

Helmut Waldmann

Johann Grolig

Gebhard Rauleder

Wolfgang Biedermann

A process has been provided for the purification of crude anthraquinone made by (1) oxidation of naphthalene to naphthoquinone (2) reaction of the oxidation product with butadiene to give tetrahydroanthraquinone and (3) oxide-hydrogenation of this reaction product with molecular oxygen to yield the crude anthraquinone, then optionally separating naphthalene, phthalic anhydride and low-boiling compounds from said crude anthraquinone. The purification of said crude anthraquinone is effected by treatment with an oxygen compound or mixture of oxygen compounds of the elements of the 1st and/or 2nd main group of the periodic system at elevated temperature, if desired in the presence of an inert solvent and the purified anthraquinone is isolated by physical separation methods from the products treated.

Process for the purification of crude anthraquinone

An improved process has been invented for the production of (1-chloroethenyl)-oxirane which comprises dehydrochlorinating (1,2-dichloroethyl)-oxirane with a solution of the sodium salt of an alcohol having at least 5 carbon atoms in said alcohol and separating the (1-chloro-ethenyl)-oxirane from the reaction mixture.

Process for the preparation of (1-chloroethenyl-) oxirane

Process for the production of 2-chlorobuta-1,3-diene (chloroprene) which comprises reacting 3,4-dichlorobut-1-ene and sodium butylate in n-butanol to produce a reaction mixture containing the 2-chlorobuta-1,3-diene and sodium chloride in the n-butanol with the sodium chloride being a suspended solid. The reaction mixture is distilled in a distillation column to separate the 2-chlorobuta-1,3-diene as top product and n-butanol having the sodium chloride suspended therein as sump product. The reaction can be performed in the distillation column.

Process for the preparation of 2-chlorobuta-1,3-diene

1,4-NAPHTHOQUINONE IS REMOVED FROM PHTHALIC ANHYDRIDE BY HEATING WITH ELEMENTARY SULFUR AT TEMPERATURES IN THE RANGE OF FROM 200.degree. TO 300.degree. C.

Process for removing 1,4-naphthoquinone from phthalic anhydride

A process for producing chloroprene from 3,4-dichlorobutene-1 and sodium hydroxide solution wherein a dehydrated mixture of n-butanol and aqueous sodium hydroxide solution is reacted with 3,4-dichlorobutene-1 to form chloroprene and solid sodium chloride.

Growing community of inventors

Leverkusen, Germany

Rupert Wenzel