The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 05, 1991
Filed:
Dec. 28, 1989
Robert Hassig, Gipf-Oberfrick, CH;
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
There is disclosed a process for the preparation of isothiocyanates of formula ##STR1## wherein R.sub.1 and R.sub.2 are each independently of the other C.sub.1 -C.sub.6 alkyl and R.sub.3, R.sub.4 and R.sub.5 are each independently of the other hydrogen, halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, trifluoromethyl or nitro, which process comprises an amine of formula ##STR2## with ammonium thiocyanate or an alkali metal thiocyanate, in the presence of acid and an inert solvent, to the thiourea of formula ##STR3## and cleaving said thiourea by heating. The essential feature of this process consists in carrying out the reaction of the amine of the above formula with ammonium thiocyanate or an alkali metal thiocyanate in the presence of 0.5-5% by weight of water, based on the total weight of the reaction mixture. The isothiocyanates of the above formula are intermediates for the synthesis of pesticidal compounds.