反应详情

6.15 g (0.03 mole) of 2,4-dichloro-thieno[3,4-d]pyrimidine are suspended in 250 ml. of absolute alcohol at 0°C. Whilst agitating constantly a solution of 0.03 mole sodium ethylate in ethyl alcohol is added drop by drop. The speed of addition is regulated in such a manner that the temperature of the reaction medium is maintained at between 0° and 5°C. One obtains a clear solution in which a precipitate is gradually formed. When the addition is completed, the agitation is continued for a further 2 hours at ordinary temperature. The reaction mixture is then poured into 2 liters of iced water and the precipitate formed is filtered off, washed with water and then dried in vacuo. After recrystallization from toluene, 5.2 g of 2-chloro-4-ethoxythieno[3,4-d]pyrimidine are obtained (81% of theory). M.P. 136°-140°C.

1. customat 0°C
2. additionis added drop by drop
3. additionThe speed of addition
4. temperatureis maintained at between 0° and 5°C
5. customOne obtains a clear solution in which a precipitate
6. customis gradually formed
7. additionWhen the addition
8. customthe precipitate formed
9. filtrationis filtered off
10. washwashed with water
11. customdried in vacuo
12. customAfter recrystallization from toluene, 5.2 g of 2-chloro-4-ethoxythieno[3,4-d]pyrimidine
13. customare obtained (81% of theory)