反应详情

50 ml of absolute glacial acetic acid and 35 g of potassium acetate were added to a solution of 57.7 g (0.16 mole) of 65% strength 3-chloromethyl-5-dichloromethyl-2-phthalimidopyrazine in 1,000 ml of dimethyl sulfoxide, and the mixture was then stirred for three days at room temperature. Thereafter, 1,000 ml of dichloromethane and 1,000 ml of ice-water were added to the reaction mixture, the resulting mixture was mixed thoroughly, and phase separation was effected. The aqueous phase was extracted once with 500 ml of dichloromethane and once with 250 ml of dichloromethane. The combined organic phases were washed twice with 1,000 ml of water, dried over sodium sulfate and evaporated down in a rotary evaporator. The blackish brown oil was taken up in 20 ml of methanol at the boil, and the solution was left to crystallize at room temperature. The product was then suspended in a little diethyl ether, filtered off and dried. The crystals were then recrystallized again from methanol. 30.6 g (77% of theory) of 3-acetoxymethyl-5-dichloromethyl-2-phthalimidopyrazine of melting point 117°-118° C. were obtained. 1H-NMR (270 MHz, CDCl3): δ1.9 (s, 3H), 5.3 (s, 2H), 6.9 (s, 1H), 8.1 (m, 4H), 9.1 (s, 1H).

1. additionthe resulting mixture was mixed thoroughly
2. customphase separation
3. extractionThe aqueous phase was extracted once with 500 ml of dichloromethane and once with 250 ml of dichloromethane
4. washThe combined organic phases were washed twice with 1,000 ml of water
5. dry with materialdried over sodium sulfate
6. customevaporated down in a rotary evaporator
7. waitthe solution was left
8. customto crystallize at room temperature
9. filtrationfiltered off
10. customdried
11. customThe crystals were then recrystallized again from methanol