GB863060A - Sulphanilamido-pyrazoles - Google Patents

Abstract

The invention comprises sulphanilamidopyrazoles of the formula: <FORM:0863060/IV (b)/1> wherein R1 and R2 are alkyl (e.g. methyl, ethyl, n-propyl and isopropyl) or cycloalkyl (e.g. cyclohexyl) radicals, R1 and R2 together containing 2-8 carbon atoms, and acyl derivatives of these compounds, and their preparation either by reacting a benzensulphonyl halide bearing a p-amino or p-acylaminosubstituent with the appropriate substituted 5-amino-pyrazole-1 : 2, or by reacting an acylacetyl sulphonamide <FORM:0863060/IV (b)/2> wherein W is a p-amino- or p-acylamino group, with a hydrazine derivative H2N,NHR1 or a functional derivative thereof, in an acid medium, the acylamino group W in the above processes being subsequently converted an amino group by saponification, if desired. 5-Amino-pyrazoles bearing substituents R1 and R2 in the 1- and 3-positions, used as starting materials, are made by reacting an acylacetonitrile R2CO,CH2,CN with a hydrazine H2N,NHR1. N1-Acylacetyl-sulphonamides <FORM:0863060/IV (b)/3> used as starting materials are made by the reaction of an alkali-metal salt of a sulphonamide with a phenyl ester of a b -keto-carboxylic acid or by the known diketene method.