New 3-(2'-benzimidazolyl)imidazo[1,2-a]pyridinium mesomeric betaines. Synthesis and structure
作者:Jose M. Minguez、Teresa Gandasegui、Juan J. Vaquero、Julio Alvarez-Builla、Jose L. Garcia-Navio、Federico Gago、Angel R. Ortiz、Pilar Gomez-Sal、Rosario Torres、Maria Melia Rodrigo
DOI:10.1021/jo00074a033
日期:1993.10
Reaction of N-[(2'-benzimidazolyl)methyl]pyridinium salts 2 with isothiocyanates results in a series of 3-(2'-benzimidazolyl)imidazo[1,2-a]pyridinium 2-thiolate derivatives 3 classified as conjugated mesomeric betaines. S-Methylation followed by deprotonation easily converts 3 into a new family of conjugated betaines 5. Semiempirical molecular orbital calculations provide complementary information to the X-ray analysis and experimental dipole moments of both betaines.