4-Diazo-4H-imidazole-5-carboxamide → 3-(2-(tert-Butyldimethylsilyloxy)ethyl)-4-oxo-3,4-dihydroimidazo[5,1-d][1,2,3,5]tetrazine-8-carboxamide

Participants

Reaction Steps

Crude 2-(tert-butyldimethylsilyloxy)ethyl isocyanate (422 mg, 2.097 mmol) was added drop wise to a solution of 5-diazoimidazole-4-carboxamide (250 mg, 1.823 mmol) in dimethylsulfoxide (2.5 mL) and the reaction mixture was stirred at room temperature. After 16 hours, the crude reaction mixture was applied to reverse phase silica (C18 silica) and eluted with water and then acetonitrile. The acetonitrile fractions were combined and purified by flash column chromatography (SiO2, gradient 0-100% acetonitrile in dichloromethane) to furnish the title compound as a white solid. Yield: 40 mg, 0.12 mmol, 6.5%. LCMS (ES+) m/z 339 (M+H)+ at 3.19 minutes. 1H NMR (400 MHz, d6-DMSO) δ: 8.87 (1H, s), 7.83 (1H, br s), 7.70 (1H, bs), 4.41 (2H, t), 3.98 (2H, t), 0.78 (9H, t), −0.03 (6H, s).

Provenance & Evidence