To confirm the proposed structures of the minor metabolites of a potential gastroprokinetic agent, mosapride, 4-amino-5-chloro-2-ethoxy-3-hydroxy-N-(2-morpholinylmethyl) benzamide (3) and the N-(5-oxo-2-morpholinyl)-methyl analogue 4 were prepared. As the common intermediate, 2-ethoxy-3-hydroxy-4-nitrobenzoic acid (15) was propared via the regioselective ethylation of 2, 3-dihydroxybenzaldehyde (10) and subsequent nitration of ...
