Water → 2-Chloro-4-ethoxy-thieno[3,4-d]pyrimidine

Participants

Reaction Steps

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.

Provenance & Evidence