Synthesis and properties of 5-furyl(aryl)-?2-1,2,4-triazolines and -?2-1,3,4-thiadiazolines. Molecular and crystal structure of 2-acetylamino-5-phenyl-?2-1,3,4-thiadiazoline

Abstract

We show that upon acylation of arylidene amidrazones of 5-nitro-2-furancarboxylic acid, 3-(5-nitro-2-furyl)-Δ2-1,2,4-triazolines or 5-(5-nitro-2-furyl)-1,2,4-triazole are formed (depending on the structure of the arylidene moiety). Δ2-1,3,4-thiadiazolines are obtained by reaction of thiosemicarbazones of aromatic and furaldehydes and furan ketones. We discuss schemes for closure of the triazolidine, triazole, and thiadiazoline rings. We describe the molecular structure of 2-acetylamino-4-acetyl-5-phenyl-Δ2-1,3,4-thiadiazoline.