Two-Step One-Pot Reductive Amination of Furanic Aldehydes Using CuAlOx Catalyst in a Flow Reactor.

Aminomethylhydroxymethylfuran derivatives are well known compounds which are used in the pharmaceutical industry. Reductive amination of 5-hydroxymethylfurfural (HMF) derived from available non-edible lignocellulosic biomass is an attractive method for the synthesis of this class of compounds. In the present study, the synthesis of N-substituted 5-(hydroxymethyl)-2-furfuryl amines and 5-(acetoxymethyl)-2-furfuryl amines was performed by two-step process, which includes the condensation of furanic aldehydes (HMF and 5-acetoxymethylfurfural) with primary amines in methanol on the first step and the reduction of obtained imines with hydrogen in a flow reactor over CuAlOx catalyst derived from layered double hydroxide on the second step. This process does not require isolation and purification of intermediate imines and can be used to synthesize a number of aminomethylhydroxymethylfurans in good to excellent yield.