反应详情

6-chloro-N4-(4-chlorophenyl)pyrimidine-4,5-diamine obtained in step 1 (1.5 g, 5.88 mmol) was dissolved in triethyl ortho propionate (11.8 ml, 58.8 mmol) at room temperature. Ethanesulfonic acid (0.48 mL, 5.88 mmol) was added slowly to the resulting solution at 0 r and warmed to room temperature. The reaction mixture thus obtained was stirred for 6 hours at 50° C. The resulting mixture was filtered with NaHCO3(aq)/H2O. The collected solid was dried under reduced pressure to obtain the title compound (1.39 g, 81%) as white solid.

1. customThe reaction mixture thus obtained
2. filtrationThe resulting mixture was filtered with NaHCO3(aq)/H2O
3. customThe collected solid was dried under reduced pressure