Solution-phase synthesis of tertiary amines via reductive amination-alkylation with ethyl p-aminobenzoate

Combinatorial chemistry is a means of rapidly generating large numbers of diverse molecules for the identification of novel molecular properties. This study will describe the attempt to synthesize, characterize and purify of a library of tertiary amine derivatives of ethyl p-aminobenzoate by solution-phase combinatorial synthesis. In this study, indirect reductive amination and subsequent alkylation of ethyl p-aminobenzoate is expected to produce thirty-five structurally related analogs. HPLC and LC-MS analysis of the resultant library however, shows that reduction of the imine intermediates with sodium triacetoxyborohydride also results in reduction of the ester functionality which prevents the subsequent alkylation reaction. A mechanism for these results will be proposed