Agfa-gevaert Ag

Gerhard Lutze

Erich Wolff

Klaus Kirschke

Ernst Schmitz

Pyrazolo[5,1-c][1,2,4]triazoles of the general formula I ##STR1## in which R.sup.1 and R.sup.2 represent alkyl, cycloalkyl, aralkyl, aryl, alkoxy or heterocyclic radicals, R.sup.3 is hydrogen, halogen or an alkyl, cycloalkyl, aralkyl, aryl or heterocyclic radical bonded via a hetero atom, wherein R.sup.2 and R.sup.3 may be closed to form a ring, and R.sup.4 is hydrogen or an acyl radical, are prepared from 3(5)-amino-pyrazoles of the general formula II ##STR2## in which R.sup.2 and R.sup.3 have the abovementioned meaning, by reaction with a hydroximoyl halide of the general formula III ##STR3## in which R.sup.1 has the abovementioned meaning and X represents chlorine or bromine, in the presence of a tertiary base to give a 5-amino-1-hydroximoyl-pyrazole, subsequent reaction with an aliphatic or aromatic sulphonyl chloride in the presence of a tertiary base to give an O-sulphonated 5-amino-1-hydroximoyl-pyrazole, acylation to give an O-sulphonated 5-acylamino-1-hydroximoyl-pyrazole or 5-bisacylamino-1-hydroximoyl-pyrazole and then treatment with bases. The optionally O-sulphonated 5-amino-1-hydroximoyl-pyrazoles or O-sulphonated 5-acylamino- and 5-bisacylamino-1-hydroximoyl-pyrazoles are new valuable intermediates for the synthesis of pyrazolo[5,1-c][1,2,4]-triazoles.

Growing community of inventors

Berlin, Germany

Gerhard Lutze