Preparation of 4-methyl-5-oxo-3-thioxo-tetrahydro-1,2,4,-(2H,4H)-triazines

US4436905A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventor

• Gerhard Bonse · Neunburg vorm Wald, DE

Key dates

• Filing date: Aug 9, 1982
• Grant date: Mar 13, 1984
• Expiry date: Aug 9, 2002

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D253/075
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

4-Methyl-5-oxo-3-thioxo-tetrahydro-1,2,4-(2H,4H)-triazines, which are intermediate products for known herbicides, can be prepared in high yields by a process in which an acyl cyanide of the general formula EQU R--CO--CN (II) PA0 wherein R represents an optionally substituted aliphatic radical having up to 12 carbon atoms, an optionally substituted cycloalkyl radical having 3 to 10 carbon atoms, an optionally substituted phenyl or naphthyl radical or an optionally substituted heterocyclic radical, is reacted with a carboxylic acid anhydride of the general formula EQU R.sup.1 --CO--O--CO--R.sup.1 (II) PA0 in which R.sup.1 represents an optionally substituted aliphatic radical having up to 8 carbon atoms or an optionally substituted phenyl radical, in the presence of a strong acid and, if appropriate, in the presence of a solvent, at a temperature between -50.degree. and 150.degree. C., and the reaction mixture thus obtained is then reacted directly with 4-methyl-thiosemicarbazide (CH.sub.3 --NH--CS--NH--NH.sub.2).