Process Intensification of Continuous Flow Synthesis of Tryptophol

Abstract

A continuous flow synthesis of tryptophol is developed in a tubular reactor at different temperatures and flow rates, by Fischer indole synthesis route using phenyl hydrazine hydrochloride (PHH) and 2,3-dihydrofuran (DHF) as starting materials. The maximum conversion of PHH was 93%, and the yield of tryptophol was 72% in 6 min. A kinetic model is proposed for the process by taking into account the formation of intermediate species. The reactor was simulated in COMSOL platform for temperature profiles in the reactor, which were subsequently used to estimate the kinetic parameters of the reaction. The reaction was further intensified by executing the reaction in a continuous microwave reactor (CMWR), at different flow rates and at different power. The maximum conversion of PHH was obtained to be 91%, and the yield of tryptophol was 95% in 5 min using CMWR.