反应详情

6-Amino-1,3-bis(cyclohexylmethyl)uracil (from step (b), 25.0 g) was dissolved in glacial acetic acid (440 ml), water (440 ml) and ethanol (440 ml) a reflux. To this solution was added sodium nitrite (5.65 g). The resulting mixture was stirred as it cooled slowly to ambient temperature. The lavender precipitate was filtered off, washed with 1:1 water-ethanol and dried to give 6-amino-1,3-bis(cyclohexylmethyl)-5-nitrosouracil as light purple crystals (23.46 g, 86%), m.p. 240-243° C. dec with effervescence; 1H-NMR (DMSO-d6) δ: 13.23 (br s, 1, ═NOH), 9.00 (br s, 1, ═NH), 3.73 (br t, J=6.86, 4, 2 NCH2), 2.0-1.6 and 1.7-1.1 (both m, total 22, 2 cyclohexyl).

1. filtrationThe lavender precipitate was filtered off
2. washwashed with 1:1 water-ethanol
3. customdried