反应详情

To a solution of ethyl 5-amino-1-methylpyrazole-4-carboxylate (1.6 9 g) (P. Schmidt et al. Helv. Chim. Acta., 1959, 42, 349) in tetrahydrofuran (30 ml) was added at 0° C. sodium hydride (about 60% in oil, 0.48 g). The mixture was stirred for one hour at room temperature. To the reaction mixture was added portionwise at 0° C. 4-bromomethyl-2'-cyanobiphenyl (3.27 g). The mixture was stirred overnight at room temperature. The reaction mixture was poured into a saturated aqueous solution of ammonium chloride, which was extracted with ethyl acetate. The extract was washed with water and a saturated aqueous saline solution, followed by drying over magnesium sulfate. The solvent was distilled under reduced pressure to give crude crystals. Recrystallization from ethyl acetate-isopropyl ether afforded the title compound as colorless crystals (2.47 g, 69%), m.p. 107°-108° C.

1. additionTo the reaction mixture was added portionwise at 0° C
2. stirringThe mixture was stirred overnight at room temperature
3. extractionwas extracted with ethyl acetate
4. washThe extract was washed with water
5. dry with materialby drying over magnesium sulfate
6. distillationThe solvent was distilled under reduced pressure
7. customto give crude crystals
8. customRecrystallization from ethyl acetate-isopropyl ether