Cyclization and oxidation of N-substituted phenyl-N’-(2-methyl-3-phenylpropenoyl)thioureas

Abstract

The synthesis of 1,3-thiazines, 2-thiouracils and ureas from N-substituted phenyl-N’-(2-methyl-3-phenylpropenoyl)thioureas by intramolecular cyclization or oxidation under various conditions is described. The structure of products was verified by IR, 1H NMR and mass spectral evidence.

Reactions of N‐alkenyl Thioureas with p‐alkoxyphenyltellurium Trichlorides

“…The reaction of thioureas 1 – 5 with p ‐alkoxyphenyltellurium trichlorides was carried out in chloroform at room temperature (Scheme ). Thioureas 1 – 5 contain several reaction centers, and this is why the action of electrophilic reagents can lead to the formation of both addition and cyclization products . We have determined that only products 6 – 11 are formed via the action of p ‐alkoxyphenyltellurium trichlorides on thioureas 1 – 3 in chloroform, which was proven by the data of 1 H NMR and 13 C NMR spectra.…”

“…Reactions of N ‐alkenyl thioureas with electrophilic reagents can lead to the formation of addition products or heterocyclic systems. Thus, when N ‐allyl‐ N ′‐arylthiourea reacts with halogens or arylselenenyl chloride, then the thiazoline or thiazolidine cycles are formed . Furthermore, N ‐β‐bromoallyl‐N′‐phenylthiourea can be cyclized to thiazole via the action of potassium carbonate .…”

Reactivity and diverse synthetic applications of acyl isothiocyanates

“…[92][93][94] Treatment of isothiocyanate 167 with amines in benzene or acetone afforded the corresponding N-substituted N'-(hexa-2,4-dienoyl)thioureas 168 in 79-92 % yields (Scheme 52). 95 Boron trifluoride-catalyzed cyclization of thioureas 168 in chloroform resulted into the formation of the 2-substituted 6-(propen-l-yl)-5,6-dihydro-4H-l,3-thiazin-4-ones 169.…”