反应详情

To a solution of 4 (1.00 g, 3.35 mmol) in 50% aqueous acetic acid at 0°, sodium nitrite (0.31 g, 4.55 mmol) was added slowly. The reaction mixture was kept at 0° with stirring for 3 h, during which time crystals started to precipitate out. The product was collected by filtration, washed with water, cooled methanol, ether, and dried. The filtrate was concentrated and an additional fraction of crystals was obtained. The combined product was recrystallized from methanol to yield 0.77 g (70%) of white fine needles: mp 159°-160° dec.: uvλmaxEtOH 264 nm (ε11,000); uvλminEtOH 235 nm. Anal. (C12H17N5O6) C, H, N.

1. customwas kept at 0°
2. customto precipitate out
3. filtrationThe product was collected by filtration
4. washwashed with water
5. temperaturecooled methanol, ether
6. customdried
7. concentrationThe filtrate was concentrated
8. customan additional fraction of crystals was obtained
9. customThe combined product was recrystallized from methanol