Bromotrimethylsilane → HCID 9942900, compound

Participants

Reaction Steps

A solution of [(E)-4-[(2-amino-3,4-dioxo-1-cyclobuten-1-yl)amino]-2-butenyl]phosphonic acid diethyl ester (1.0 g, 3.3 mmol) and bromotrimethylsilane (4.6 mL, 35 mmol) in anhydrous 1,2-dichloroethane (30 mL) under nitrogen was refluxed for 20 minutes and then cooled and evaporated. The residue was dissolved in water (150 mL) and washed with diethyl ether (2×75 mL). The resulting material, upon concentrating the aqueous layer, was recrystallized from methanol in ethyl acetate (final volume=100 mL) to yield [(E)-4-[(2-amino-3,4-dioxo-1-cyclobuten-1-yl)amino]-2-butenyl]phosphonic acid one third hydrate as a yellow solid (0.59 g, 71%, mp 220°-230° C. (dec)); IR (KBr, cm-1): 3280, 3100, 1800, 1640; MS (-FAB): 245 (M-H); 1H NMR (DMSO, 400 MHz): δ 7.47 (br s, 3 NH), 5.63-5.58 (m, 2H), 4.10 (br s, 2H), 2.38 (d of d, J=21 and 6 Hz, 2H).

Provenance & Evidence