反应详情

5-Amino-1-β-D-ribofuranosylimidazole-4-carboxamide (5.2 g, 20 mmol) was dissolved in 40 ml hot dimethylformamide and diluted with 70 ml methanol containing 35 mg tin(II) chloride dihydrate. A solution of 0.1 mol of diazomethane in 200 ml of ether was added in portions over 45 min. After each addition, 20 mg of tin(II) chloride dihydrate was added. The resulting mixture was filtered and evaporated to give a syrup. The syrup was dissolved in 25 ml of methanol and upon cooling yielded crystalline 5-amino-1-(2-O-methyl-β-D-ribofuranosyl)imidazole-4-carboxamide which was collected by filtration and dried. Yield was 1.2 g, melting point 114°-117° C. 1H NMR (DMSO-d6) (for Compound 20) Δ ppm, 3.3 (s, 3H, CH3), 3.6 (m, 2H, 5′-CH2), 3.9 (m, 1H, 4′-CH), 4.1 (m, 1H, 2′-CH), 4.2 (in, 1H, 3′-CH), 5.2 (d, 1H, 3′-OH), 5.3 (t, 1H, 5′-OH), 5.6 (d, 1H, 1′-CH), 6.0 (broad s, 2H, 5-NH2), 6.7 (broad-d, 2H, 4-CONH2), 7.3 (s, 1H, 2-CH).

1. additionwas added
2. filtrationThe resulting mixture was filtered
3. customevaporated
4. customto give a syrup
5. temperatureupon cooling