The reactivity of the - system towards ferric chloride has been investigated. The cyclo-oxidation reaction led to the formation of 2-amino-5-thenoyl-1,3,4-thiadiazoles and 4-methyl-5-imino-2-thenoyl-Δ2-1,3,4-thiadiazolines. Their structures were proven spectro-scopically and chemically (nucleophilic attack and formation of the related 2-amino-1,3,4-thiadiazoles and 4-methyl-5-imino-Δ2-1,3,4-thiadiazolines).
