Formamide → methyl[4-(5-bromo-1-methyl-1H-pyrazol-4-yl)-1H-imidazol-1-yl]carbamate

Participants

Reaction Conditions

Reaction Steps

Methyl 2-[2-(5-bromo-1-methyl-1H-pyrazol-4-yl)-2-oxoethyl]-2-formylhydrazine carboxylate (1.20 g, 3.76 mmol) was mixed with ammonium acetate (1.16 g, 15.0 mmol), formamide (4 mL) and acetonitrile (5 mL). The reaction was heated to 130° C., and the acetonitrile was allowed to boil off for 10 minutes. Heating was continued for an additional 4 hours. After addition of water, the crude mixture was extracted eight times with ethyl acetate. The combined organic layers were dried over sodium sulfate, filtered and concentrated in vacuo; purification via silica gel chromatography (Gradient: 0% to 100% [10% methanol in ethyl acetate] in heptane) afforded the product as a pinkish solid. Yield: 800 mg, 2.67 mmol, 19% over two steps. LCMS m/z 299.8 (M+1). 1H NMR (400 MHz, CD3OD) δ 3.80 (br s, 3H), 3.90 (s, 3H), 7.52 (d, J=1.3 Hz, 1H), 7.77 (d, J=1.3 Hz, 1H), 7.85 (s, 1H).

Provenance & Evidence