反应详情

A solution of 43 g 1,3-dimethyl 8-chloro xanthine in 200 ml water and 20 ml sodium hydroxide 10N is heated to 70°-80° C., to which 27.6 ml 4-fluorobenzyl chloride are portion-wise added at this temperature within 4 hours. During this addition, 20 ml sodium hydroxide 10N are added by small portions to maintain the pH at an alkaline value. After achievement of this addition, the solution is further heated at 70°-80° for 2 hours then let to revert to room temperature under stirring. The precipitate is filtered, dried, washed with water until neutral, then dried. Thereafter it is recrystallized from acetone to recover 19 g of pure compound. It melts at 183°-184° C.

1. additionadded at this temperature within 4 hours
2. additionare added by small portions
3. temperatureto maintain the pH at an alkaline value
4. additionAfter achievement of this addition
5. temperaturethe solution is further heated at 70°-80° for 2 hours
6. customto revert to room temperature
7. filtrationThe precipitate is filtered
8. customdried
9. washwashed with water until neutral,
10. customthen dried
11. customThereafter it is recrystallized from acetone
12. customto recover 19 g of pure compound