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) at 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