Discontinuous two step flow synthesis of m-aminoacetophenone

Abstract

The continuous flow nitration of acetophenone followed by reduction of the meta isomer has been demonstrated using simple tubular reactors. Because of ease of separation of the desired isomer from the first step, both steps are made continuous, but separately. The continuous flow nitration was carried out in a safe manner in a shorter reaction time than the conventional approach. The choice of micromixer was seen to affect the performance of the nitration reaction. The effect of different parameters on the yield of the desired product was studied. The reduction step with sodium sulfide was found to be economical and could be carried out efficiently at 70°C using sodium sulfide in ethanol, using a silicone tube. Both steps were demonstrated for several hours, yielding a sufficiently large quantity (∼100 g) of m-aminoacetophenone at lab scale in a single day using simple tubular reactors.

Keywords

• acetophenone
• continuous flow synthesis
• microreactor
• nitration
• reduction