Synthesis of 2-benzyl benzoxazoles and benzothiazoles via elemental sulfur promoted cyclization of styrenes with 2-nitrophenols and N,N-dialkyl-3-nitroanilines

Abstract

Annulation of 2-nitrophenols and N,N-dialkyl-3-nitroanilines with styrenes in the presence of elemental sulfur and the base DABCO successfully yielded 2-benzyl benzoxazoles and 2-benzyl benzothiazoles, respectively.

Cobalt ferrite nanoparticles for annulation of C3-substituted nitroarenes and aryl isothiocyanates

“…Our group has recently developed a couple of methods for the synthesis of benzothiazole derivatives from N , N -dialkyl-3-nitroanilines ( IV ) as the starting material (Scheme 1, bottom). 5 The use of such nitroarenes avoids the pre-functionalization of ortho C–H bonds to nitroarenes prior to cyclization. 6 It should also be noted that elemental sulfur is often essential to promoting the transformations of N , N -dialkyl-3-nitroanilines.…”