N,n-dimethyl-o-(1-methyl 4 - cyano 5-alkylmecapto-pyrazole-3yl) carbaminic acid esters - insecticides

摘要

Insecticidal carbaminic esters are of formula (I):- where R = (1-4C) alkyl. (1) are prepd. from the 3-hydroxy deriv. by (a) condensing with Me2NCOCl;(b) condensing with COCl2 below Ph 7, followed by Me2NH; (c) condensing with COCl2 at pH 8, followed by Me2HN. In each case solvents at 0-150 degrees are used, optionally with base.