Tetrazole compounds useful as intermediates for the preparation of herbicides

摘要

Tetrazole compounds of formula I may be useful as intermediates for the preparation of sulfonamide or sulfonyl urea growth regulators or herbicides (e.g. Azimsulfuron). R1 is H, Cl, Br or I; R2 is H or C1-7 alkyl (which may be substituted with a substituted phenyl group); R3 is optionally substituted C1-7 alkyl or C6-14 aryl; with the proviso that when R1 is H R2 is not methyl. The compound may be 5-(5-chloro-1-methyl-1H-pyrazol-4-yl)-2H-tetrazole. Compound I may be made by reaction of a 1H-pyrazole-4-carbonitrile of formula II with sodium azide.