By reaction of 3-aryl(heteryl)-4-chloromethylpyrazoles with thiourea and sodium thiocyanate respectively 3-aryl(heteryl)-4-mercaptomethylpyrazoles and 3-aryl(heteryl)-thiocyanatomethylpyrazoles were obtained. The latter were subjected to thermal isomerization into 3-aryl(heteryl)-isothiocyanatomethylpyrazoles.
3-Aryl(heteryl)pyrazole-4-carbaldehydes were reduced with sodium tetrahydridoborate under mild conditions to give 3-aryl(heteryl)-4-hydroxymethylpyrazoles which were converted into the corresponding 4-chloromethyl derivatives by treatment with thionyl chloride. The subsequent reaction with triphenylphosphine led to formation of triphenyl(4-pyrazolylmethyl)phosphonium chlorides, and Wittig reaction of the latter with aromatic or heteroaromatic aldehydes yielded 4-[2-aryl(heteryl)ethenyl]pyrazoles.