Process and intermediates for the preparation of pyroxasulfone

Abstract

The invention relates to a process for preparing a key intermediate of Formula (I) in the synthesis of pyroxasulfone. The process comprises reacting an isoxazole of Formula (II) with a thionating reagent to create an S-substituted thioisoxazole of Formula (III); and combining the S-substituted thioisoxazole of Formula (III) with a pyrazole of the Formula (IV) by introducing a methylene bridge, to obtain a compound of Formula (I). The invention also relates to novel S-substituted thioisoxazole of Formula (III) and processes of preparation thereof, wherein L is halogen or an anionic residue derived from an acid; R is an organic residue derived from a suitable thionating reagent: dimethyl thioformamide, thiosulfate salts, dithiooxamide, alkyl xanthate salts, thiobenzamide, V-substituted thiourea and thioacetate salts.

CPC Classifications