Methyl acetoacetate → Methyl 3-{[4-(acetylamino)phenyl]amino}but-2-enoate

Participants

Reaction Conditions

Reaction Steps

A suspension of 4-aminoacetanilide (2) (253 g, 1.68 mol) and methyl acetoacetate (215 g, 1.85 mol) in MeOH (0.75 L) was heated to reflux. The resulting solution was held at reflux for 16 h and then cooled to 5° C. The resulting off-white precipitate was filtered and washed with MTBE (3×200 mL) to give butenoate 3 (195 g, 47% yield). The mother liquor was concentrated in vacuo and filtered to give a second crop of 3 as pale pink solids (141 g, 34% yield, 81% overall yield). 1H NMR (DMSO) δ 10.22 (s, 1 H), 9.97 (s, 1 H), 7.57 (d, 2 H), 7.11 (d, 2 H), 4.65 (s, 1 H), 3.56 (s, 3 H), 2.04 (s, 3 H), 1.94 (s, 3 H); 13C NMR (DMSO) δ 169.64, 168.07, 159.33, 136.48, 133.55, 124.52, 119.44, 84.47, 49.77, 23.81, 19.68.

Provenance & Evidence