反应详情

温度

0 °C

Over a period of about 1 h, benzyloxycarbonyl chloride (52 ml; 0.36 mol) was added dropwise to a suspension of cytosine (8, 20.0 g;0.18 mol) in dry pyridine (1000 ml) at 0° C. under nitrogen in oven-dried equipment. The solution then was stirred overnight, after which the pyridine suspension was evaporated to dryness, in vacuo. Water (200 ml) and 4 N hydrochloric acid were added to reach pH ˜1. The resulting white precipitate was filtered off, washed with water and partially dried by air suction. The still-wet precipitate was boiled with absolute ethanol (500 ml) for 10 min, cooled to 0° C., filtered, washed thoroughly with ether, and dried, in vacuo. Yield 24.7 g (54%). M.p.>250° C. Anal. for C12H11N3O3. Found(calc.); C, 58.59(58.77); H, 4.55(4.52); N, 17.17(17.13). No NMR spectra were recorded since it was not possible to get the product dissolved.

1. customafter which the pyridine suspension was evaporated to dryness, in vacuo
2. additionWater (200 ml) and 4 N hydrochloric acid were added
3. filtrationThe resulting white precipitate was filtered off
4. washwashed with water
5. custompartially dried by air suction
6. waitThe still-wet precipitate was boiled with absolute ethanol (500 ml) for 10 min
7. filtrationfiltered
8. washwashed thoroughly with ether
9. customdried, in vacuo
10. customto get the product
11. dissolutiondissolved