反应详情

10 G. of dimethyl 6-[3,6-dihydro-1(2H)-pyridyl]-2,4-pyrimidinedicarbamate-3-oxide are dissolved in 350 ml. of chloroform and 100 ml. of methanol. The solution obtained is treated with 5 g. of sodium carbonate in 100 ml. of water and the resulting mixture is stirred at room temperature for 80 hours. The mixture is then diluted with 250 ml. of water and adjusted to pH 12.5 with concentrated sodium hydroxide. The mixture is then stirred for 30 minutes and then the two phases are separated. The aqueous phase is extracted twice with methylene chloride. The combined organic extracts are dried over magnesium sulfate and evaporated to dryness under reduced pressure. The residue is chromatographed over silica gel using a mixture of chloroform and ethanol (90:10) for the elution, there being obtained pure methyl 2-amino-6-[3,6-dihydro-1(2H)-pyridyl]-4-pyrimidinecarbamate-3-oxide having a melting point of 174°-176° C.

1. customThe solution obtained
2. additionis treated with 5 g
3. additionThe mixture is then diluted with 250 ml
4. customthe two phases are separated
5. extractionThe aqueous phase is extracted twice with methylene chloride
6. dry with materialThe combined organic extracts are dried over magnesium sulfate
7. customevaporated to dryness under reduced pressure
8. customThe residue is chromatographed over silica gel using
9. additiona mixture of chloroform and ethanol (90:10)
10. washfor the elution, there