反应详情

Guanidine hydrochloride (IIIc) (10 g, 0.1 mol) was added to 1 M ethanolic sodium ethoxide (100 ml) and the mixture was stirred for 10 minutes at room temperature. Sodium chloride was removed from the mixture by filtration, and the filtrate was condensed to a syrup in vacuo below 35°. To the residue was added 1,3,6-trimethyluracil (800 mg, 0.005 mol) and the mixture was heated at ~90° for 6 hours under nitrogen. The reaction mixture was dissolved in water (20 ml) and the solution added to a column of Amberlite IRC-50 (H+) (30×3 cm diameter) and the column was washed with water. The uv absorbing fractions were collected and evaporated to dryness in vacuo. The solid residue was recrystallized from water to give 6-methylisocytosine (IIb, R1 =H, R2 =methyl) (320 mg, mp 290°-292° dec.). The uv and ir characteristics were identical with those of an authentic sample of 6 -methylisocytosine.

1. customSodium chloride was removed from the mixture by filtration
2. customcondensed to a syrup in vacuo below 35°
3. temperaturethe mixture was heated at ~90° for 6 hours under nitrogen
4. additionthe solution added to a column of Amberlite IRC-50 (H+) (30×3 cm diameter)
5. washthe column was washed with water
6. customThe uv absorbing fractions
7. customwere collected
8. customevaporated to dryness in vacuo
9. customThe solid residue was recrystallized from water