THE SYNTHESIS AND TAUTOMERIZATION OF KETENE AMINALS WITH BENZIMIDAZOLINE RING

Article abstract of DOI:10.1016/S0040-4020(01)88754-8

The first isolation of benzimidazoline ring substituted ketene aminals 7a-c and/or their amidine tautomers 7'b-d, which were synthesized by the reactions: (1) benzoyl substituted ketene mercaptals 3 with N-methyl-o-phenylenediamine 4, and (2) 1,2-dimethylbenzimidazole 5 with ethyl benzoates 6, were disclosed.The tautomeric equilibrium between 7 and 7', along with benzothiazoline and benzoxazoline ring substituted ketene N,S-acetals 8 and 8' and ketene N,O-acetals 9 and 9', were discussed.