Synthesis of ethyl 4-(3,4,5-trimethoxycinnamoyl)- ) 72,5-14C{ piperazinyl acetate. )]

Abstract This paper describes the synthesis (i) of ethyl 4‐(3, 4, 5‐trimethoxycinnamoyl) ‐ [2, 5‐ 14 C] piperazinyl acetate via [2, 5‐ 14 C] piperazine, and ethyl [ 2, 5‐ 14 C] piperazinyl acetate, and (ii) of ethyl 4‐(3, 4, 5‐trimethoxy [β‐ 14 C] cinnamoyl)piperazinyl acetate via 3, 4, 5‐trimethoxybromobenze and 3, 4, 5‐trimethoxybenz [ 14 C] aldehyde. The unequivocal preparation of 3, 4, 5‐trimethoxybromobenzene is described, and other methods for the preparation of 3, 4, 5‐trimethoxybenz [ 14 C] aldehyde are examined.