Basf Aktiengesellschaft

Gerhard Kilpper

Johannes Grimmer

Helmut Hoch

Peter Tonne

Jochem Henkelmann

Eckhard Hetzel

Hans Christoph Horn

Thomas-Michael Kahl

Walter Maier

Winfried Ludwig

Preparation of quinophthalone derivatives

1-Nitroanthraquinone-2-carboxylic acid of the formula I ##STR1## is prepared by treating novel 2-substituted 1-nitroanthraquinones of the general formula II ##STR2## where R is --CH.dbd.CH--R.sup.1 or --CH.sub.2 --CHO, where R.sup.1 is C.sub.1 -C.sub.5 -dialkylamino or a cyclic 5- or 6-membered amine which may contain further hetero atoms, with oxidizing agents free of heavy metal.

Preparation of 1-nitroanthraquinone-2-carboxylic acid

Anthranilic acid amides are prepared by mixing phthalamic acid with a caustic alkali solution, a catalyst and a hypohalite, allowing the mixture to stand for from 1 to 1,000 seconds, then introducing the amine and thereafter addig acid until the pH of the mixture is from 6 to 8. The anthranilic acid amides obtainable by the process of the invention are valuable starting materials for the preparation of dyes, scents and pesticides.

Preparation of anthranilic acid amides

A process for the continuous preparation of phthalimide by reacting phthalic anhydride with ammonia in about the stoichiometric ratio, in a mixing apparatus and subsequently in a reaction tube at a particular flow velocity and a particular temperature. The phthalimide obtainable by the process of the invention is a valuable starting material for the preparation of dyes, pesticides and pigments, especially copper phthalocyanines.

Continuous preparation of phthalimide

A process for the continuous preparation of isatoic anhydrides by two-stage reaction of an alkali metal phthalamate and/or alkali metal phthalimidate with an alkali metal hypohalite, the first stage being carried out substantially adiabatically and both stages being carried out at high flow rates, wherein phthalimide and/or phthalamic acid is first dissolved in a certain amount of an alkali metal hydroxide solution, the resulting solution is mixed with a hypohalite and reacted at a particular temperature, acid is then added and the reaction is completed at a particular temperature. The compounds obtainable by the process of the invention are valuable starting materials for the preparation of dyes, crop protection agents and scents.

Continuous preparation of isatoic anhydride

A process for the continuous preparation of anthranilic acid by a two-stage reaction of an alkali metal phthalamate and/or an alkali metal phthalimidate with an alkali metal hypohalite, the first stage being carried out substantially adiabatically and both stages being carried out at high flow rates and different temperatures, wherein first the phthalimide and/or phthalamic acid is dissolved in a defined excess amount of alkali metal hydroxide solution and the solution is only then mixed, and reacted, with the hypohalite, without further addition of excess alkali. The products are starting materials for the preparation of dyes and scents.

Continuous preparation of anthranilic acid

Anthranilic acid is manufactured continuously by reacting an alkali metal phthalamate and/or phthalimidate with an alkali metal hypohalite in a reaction tube, the resulting anthranilic acid being treated, during or after the reaction, with reducing agents in two steps, the reducing agents employed in the two steps being different from one another, and an alkali metal dithionite or alkali metal formaldehyde-sulfoxylate being used as the reducing agent in the second treatment step. The product is a starting material for the preparation of dyes, crop protection agents and scents.

Growing community of inventors

Battenberg, Germany

Gerhard Kilpper