- A. W. Oxford, R. J. Davies, R. A. Coleman, K. L. Clark
- PCT Int. Appl. WO 2005080367
A short and effective synthesis of ethyl 3-(3-aminophenyl)propanoate is presented, employing a tandem Knoevenagel condensation/alkylidene reduction of 3-nitrobenzaldehyde with Meldrum's acid in TEAF (triethylammonium formate) followed by reduction of the intermediate 3-(3-nitrophenyl)propanoic acid by stannous chloride in ethanol. The use of stannous chloride as the reducing agent in ethanol enabled the simultaneous esterification of the carboxylic acid. Thus, stannous chloride was acting simultaneously as a Lewis acid, which activates the carboxylic acid towards a nucleophilic attack by ethanol.