Process for the preparation of alkylhydroxyanilinothiotriazine derivatives

US5086173A · kind A · utility

Assignee

• Ciba-Geigy · US

Inventors

• Wolfgang J. Tritschler · Binzen, DE
• Heinz Steiner · Bubendorf, CH
• Helmut Prestel · Bruchsal, DE
• Rudolf Maul

Key dates

• Filing date: May 13, 1991
• Grant date: Feb 4, 1992
• Expiry date: May 13, 2011

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D251/46
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the preparation of compounds of formula I ##STR1## wherein R.sub.1 and R.sub.2 are each independently of the other hydrogen, C.sub.1 -C.sub.12 alkyl, C.sub.5 -C.sub.6 cycloalkyl or phenyl, and R.sub.3 and R.sub.4 are each independently of the other C.sub.1 -C.sub.18 alkyl, C.sub.5 -C.sub.6 cycloalkyl, phenyl, phenyl which is substituted by C.sub.1 -C.sub.6 alkyl and/or hydroxy, or phenyl-C.sub.1 -C.sub.4 alkyl. The process comprises reacting a compound of formula III ##STR2## with a nitrite in aqueous or aqueous/organic medium to a compound of formula II ##STR3## extracting said compound of formula II from the reaction solution with a solvent, hydrogenating said compound, without isolation, in the cited solvent and in the presence of a palladium catalyst, to the corresponding p-aminophenol, and reacting said aminophenol, without isolation, with cyanuric chloride and a compound of formula HSR.sub.3 or HSR.sub.4 or a mixture of compounds of formulae HSR.sub.3 and HSR.sub.4. The products are obtained in high yield and purity.