A green, aza-Michael reaction is described that can be used to teach undergraduate students conjugate addition of nitrogen nucleophile to an a,ß-unsaturated ester. Students analyze spectral data of the product obtained from the assigned reaction to determine product structure and propose the mechanism of its formation. The experiment requires simple glassware and can be performed during a 3 to 4 h laboratory period in the second semester of introductory organic chemistry after acyl substitution and conjugate addition have been covered in a lecture class.