反应详情

To a solution of compound 4 (50 g, 321.7 mmol) in 1-butanol (1 L) was added hydrazine monohydrate (150 mL, 3.2 mol), and the mixture was refluxed for 4 h. The mixture was cooled to room temperature and concentrated. The precipitate was successively washed on filter with water (2×) and Et2O (2×) and dried in vacuo overnight to give compound 5 (44 g, 88%) as a yellow solid. 1H NMR (DMSO-d6, 300 MHz): δ 5.53 (s, 2H); 7.94 (dd, 1H); 8.35 (dd, 1H); 12.02 (s, 1H).

1. temperaturethe mixture was refluxed for 4 h
2. concentrationconcentrated
3. washThe precipitate was successively washed
4. filtrationon filter with water (2×) and Et2O (2×)
5. customdried in vacuo overnight