The synthesis of potential insecticides. Part III. Carbamic esters of 3-cyano-4-hydroxy-thiophens and -pyrroles

Abstract

In a novel heterocyclic synthesis, the reaction of 2,3-dienenitriles with mercaptoacetates and with certain 2-amino-carboxylates gives good yields of 2-alkyl-3-cyano-4-hydroxy-thiophens and -pyrroles respectively. Ethyl o-mercaptobenzoate reacts with 2,3-dienenitriles to give 2-alkyl-4-oxothiochroman-3-carbonitriles. The hydroxy-thiophens and -pyrroles made available by this route were converted into their methyl and dimethyl carbamates for evaluation as acetylcholinesterase inhibitors.