Scheme 1. General Synthetic Route for Terfenadine (1a) and Analogues Series 1.
Reagents and conditions: (a) NaHCO3, 2-butanone/water, 85 °C, 16 h, 23–95%; (b) NaBH4, MeOH, rt, 3 h, 52–95%.
Reagents and conditions: (a) NaHCO3, 2-butanone/water, 85 °C, 16 h, 23–95%; (b) NaBH4, MeOH, rt, 3 h, 52–95%.