Synthesis of pyrrole derivatives via cycloaddition reaction of reissert hydrofluoroborate salts with α-bromoacrylamides

Abstract

An investigation of α-bromoacrylamide as a dienophile for the cycloaddition reaction of Reissert hydrofluoroborate salt of quinoline/phenanthridine has been carried out. The optimized condition has been developed for the [4+2] cycloaddition reaction of Reissert hydrofluroborate salt and a-bromoacrylamide by using K2 CO3 in DMF under moderate temperature to afford highly functionalized pyrrole derivatives (6a-f and 7a-f) in very good to excellent yield. The structures of newly synthesized compounds were established based on FT-IR, Mass, 1 H and 13C NMR spectral techniques. Besides, the structure of compound 7a has been confirmed by 2D NMR experiments (COSY and HSQC).