4-Amino-3-methylbenzoic acid → 4-Amino-N,3-dimethylbenzamide

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-amino-3-methylbenzoic acid (1 equiv), N1-((ethylimino)methylene)-N3,N3-dimethylpropane-1,3-diamine hydrochloride (1.2 equiv), methanamine hydrochloride (1.2 equiv) in DMF (1.3 M) was added sodium hydrogencarbonate (2 equiv). The reaction was stirred at 25° C. for 15 h. The reaction mixture was quenched with saturated aqueous sodium chloride and then washed with ethyl acetate. The organic phase was combined and washed with saturated aqueous sodium chloride. The organic layer was dried (anhydrous magnesium sulfate), filtered, and concentrated. The crude product was purified by silica gel column chromatography (0-90% ethyl acetate (with 10% 1N ammonia in methanol) in hexane). Concentration of the desired fractions afforded the title compound (18.4% yield) as a yellow solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 2.06 (s, 3 H) 2.71 (d, J=4.69 Hz, 3 H) 5.33 (s, 2 H) 6.56 (d, J=8.59 Hz, 1 H) 7.41 (dd, J=8.39, 2.15 Hz, 1 H) 7.45 (s, 1 H) 7.87-7.99 (m, 1 H); MS (ESI) m/z 165.4 [M+1]+.

Provenance & Evidence