ethyl 2-[(2-ethoxy-2-oxoethyl)amino]-2-oxoacetate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of N-ethoxycarbonylmethyl-oxalamic acid ethyl ester (84.0 g, 414 mmol) 2–1 in 2-propanol (500 mL) was added aminoacetaldehyde dimethyl acetal (45.7 g, 435 mmol) in one portion. After stirring overnight at room temperature, the reaction mixture was concentrated to a thick orange oil. This thick slurry was diluted with 2-propanol (300 mL) and the solid was broken up with a spatula. Filtration afforded a solid which was further rinsed with an additional portion of 2-propanol. Removal of residual 2-propanol was accomplished via high vacuum to afford a light orange solid: 1H NMR (CDCl3) δ 7.82 (br s, 1H), 7.50 (br s, 1H), 4.41 (t, 1H, 5.3 Hz), 4.24 (q, 2H, 7.1 Hz), 4.09 (d, 2H, 5.9 Hz), 3.47 (dd, 2H, 5.3, 6.2 Hz), 3.40 (s, 6H), 1.30 (t, 3H, 7.1 Hz). the reaction mixture was concentrated to a thick orange oil This thick slurry was diluted with 2-propanol (300 mL) Filtration afforded a solid which was further rinsed with an additional portion of 2-propanol Removal of residual 2-propanol to afford a light orange solid