反应详情

2 G. of 2-methoxyethyl 2-amino-6-[3,6-dihydro-1(2H)-pyridyl]-4-pyrimidinecarbamate-3-oxide are dissolved at 0° C. in 15 ml. of chloroform and 3.7 ml. of triethylamine. The cold stirred mixture is treated with 3.2 ml. of 20% phosgene in toluene. The mixture is then stirred for 4 hours, acidified with hydrochloric acid, washed with water and extracted with methylene chloride. The organic phase is dried over magnesium sulfate and the solvent is distilled off under reduced pressure. The residue obtained is crystallized from methylene chloride and ether, there being obtained pure 2-methoxyethyl 5-[3,6-dihydro-1(2H)-pyridyl]-2-oxo-2H-[1,2,4]oxadiazolo[2,3-a]-pyrimidine-7-carbamate having a melting point of 195°-196° C.

1. additionis treated with 3.2 ml
2. stirringThe mixture is then stirred for 4 hours
3. washwashed with water
4. extractionextracted with methylene chloride
5. dry with materialThe organic phase is dried over magnesium sulfate
6. distillationthe solvent is distilled off under reduced pressure
7. customThe residue obtained
8. customis crystallized from methylene chloride and ether, there