3 - Chlorine - 4 - subst. - 1,2,5 - thiadiazoles and method for their preparation

摘要

1,161,093. 3 - Chloro - 4 - hydroxy - 1,2,5- thiadiazole and ethers thereof. MERCK & CO. Inc. 13 Oct., 1966 [15 Oct., 1965], No. 45815/66. Heading C2C. The invention comprises compounds of the general formula wherein R represents hydrogen, C 1-5 alkyl, C 2-5 alkenyl, C 2-5 alkoxyalkyl, C 1-5 hydroxyalkyl or benzyl. The compounds in which R is other than hydrogen may be prepared from the compound in which R is hydrogen by reaction with a compound R-Y in the presence of a base and in a solvent, R being other than hydrogen and Y being the anion of a strong acid. The compounds in which R is hydrogen or C 1-5 alkyl may be prepared by reacting a compound of the formula RO-C(CN) = NH with sulphur monochloride and/or sulphur dichloride in a non-protonic organic solvent which must also be polar when sulphur monochloride is used. The compound in which R is hydrogen may be obtained by treating compounds in which R is other than hydrogen with a strong Lewis acid under non-aqueous conditions. Alkyl cyanoformimidates of the formula RO-C(CN) = NH, wherein R is C 1-5 alkyl, are prepared by passing chlorine into a mixture of R-OH, sodium cyanide and water.