Ammonia → HCID 57010612, compound

Participants

Reaction Steps

An ethanolic solution (40 mL) of [2-[(2-ethoxy-3,4-dioxo-1-cyclobuten-1-yl)methylamino]ethyl]phosphonic acid diethyl ester (3.00 g, 9.40 mmol) was combined with ethanolic ammonia solution (70 mL) and left for 18 hours. After concentrating in vacuo, the solid was recrystallized twice from methanol in ethyl acetate (final volume=50 mL) to yield [2-[(2-amino-3,4-dioxo-1-cyclobuten-1-yl)methylamino]ethyl]phosphonic acid diethyl ester as a solid (2.10 g, 77%, mp 130°-132° C.); IR (KBr, cm-1): 3320, 3160, 1800, 1670, 1650, 1640; MS (+FAB): 291 (MH+, 100), 196 (22), 109 (20); 1H NMR (DMSO, 400 MHz): δ 7.61 (br s NH2), 4.02-3.94 (m, 4H), 3.74 (br s, 2H), 3.13 (br s, 3H), 2.13 (d of t, J= 18 and 7.5 Hz, 2H), 1.22 (t,J=7 Hz, 6H).

Provenance & Evidence