反应详情

20.7 G. of 2,4-diamino-6-[3,6-dihydro-1(2H)-pyridyl]pyrimidine-3-oxide are mixed with 250 ml. of methylene chloride and 35 ml. of triethylamine and cooled to 5° C. 40 Ml. of chloroformic acid isobutyl ester are added dropwise while stirring. After completion of the addition, the mixture is stirred at 5° C. for 15 minutes and then at room temperature for 2 hours. The solution is treated with 200 ml. of water and extracted with methylene chloride. The organic phase is evaporated and the residue is crystallized from ethanol. There is obtained diisobutyl 6-[3,6-dihydro-1(2H)-pyridyl]-2,4-pyrimidine-dicarbamate-3-oxide, having a melting point of 137°-139° C. (decomposition).

1. additionAfter completion of the addition
2. stirringthe mixture is stirred at 5° C. for 15 minutes
3. additionThe solution is treated with 200 ml
4. extractionof water and extracted with methylene chloride
5. customThe organic phase is evaporated
6. customthe residue is crystallized from ethanol