反应详情

To 2-amino-4,6-dimethylpyrimidine (10 g) dissolved in dimethylcarbamate (80 ml) was added sodium methoxide (4.4 g) and the mixture refluxed for four hours. The mixture was cooled and acetic acid (5 ml) was added. The mixture was then partitioned between water (100 ml) and methylene chloride (300 ml). A second methylene chloride extraction of the aqueous phase was made and the combined methylene chloride phase washed with water (50 ml) containing NH4Cl. The solvent was evaporated and the residue triturated with a methylene chloride/1-chlorobutane mixture. The filtrate, on concentration and addition of hexane gave 6.7 g of the pure carbamate, m.p. 80°-85° C. IR: NH at 3200 cm-1, carbonyl at 1745 cm-1. NMR: 2.4 ppm, 2×CH3, singlet, ArH 6.75 ppm 1H, singlet, 8.9 ppm, NH, broad.

1. temperaturethe mixture refluxed for four hours
2. temperatureThe mixture was cooled
3. customThe mixture was then partitioned between water (100 ml) and methylene chloride (300 ml)
4. extractionA second methylene chloride extraction of the aqueous phase
5. washthe combined methylene chloride phase washed with water (50 ml)
6. additioncontaining NH4Cl
7. customThe solvent was evaporated
8. customthe residue triturated with a methylene chloride/1-chlorobutane mixture
9. concentrationThe filtrate, on concentration and addition of hexane