Photochemical cyclization of thioformanilides by chloranil: An approach to 2-substituted benzothiazoles

REY, VALENTINA; SORIA-CASTRO, SILVIA MERCEDES; ARGÜELLO, JUAN ELÍAS; PEÑEÑÓRY*, ALICIA BEATRIZ

TETRAHEDRON LETTERS

Elsevier

Año: 2009 vol. 50 p. 4720 - 4723

0040-4039

Abstract—2-Substituted benzothiazoles were efficiently synthesized by radical cyclization of thioformanilides induced by chloranil under irradiation in 1,2-dichloroethane and toluene at 80°C. In these solvents, hydrogen atom abstraction from the thiobenzamide by triplet chloranil was the key step as confirmed by LFP experiments. The reported methodology is simple, with good yield and the products easily isolated. © 2010 Elsevier Science. All rights reserve