Synthesis of 6-Substituted 2-Pyrrolyl and Indolyl Benzoxazoles by Intramolecular O-Arylation in Photostimulated Reactions

VICTORIA A. VAILLARD; JAVIER F. GUASTAVINO; MARÍA E. BUDEN; JAVIER I. BARDAGÍ; SILVIA M. BAROLO; ROBERTO A. ROSSI

JOURNAL OF ORGANIC CHEMISTRY

AMER CHEMICAL SOC

Lugar: Washington; Año: 2011 vol. 77 p. 1507 - 1519

0022-3263

The synthesis of a series of 6-substituted 2- pyrrolyl and 2-indolyl benzoxazoles by photostimulated C−O cyclization of anions from 2-pyrrole carboxamides, 2-indole carboxamides, or 3-indole carboxamides has been found to proceed in good to excellent yields (41−100%) in DMSO and liquid ammonia. The pyrrole and indole carboxamides are obtained in good to very good isolated yields by an amidation reaction of different 2-haloanilines with 2-carboxylic acid of pyrrole and 2- or 3-carboxylic acid of indole. To explain the regiochemical outcome of these reactions (C−O arylation vs C−N or C−C arylation), a theoretical analysis was performed using DFT methods and the B3LYP functional.