反应详情

3-(5-Mercapto-4-pyridin-4-yl-1H-pyrazol-3-yl)-benzonitrile (4.59 g, 16.1 mmol) was dissolved in dry DMF (200 mL) under nitrogen atmosphere. Solid potassium carbonate (11.1 g, 80.5 mmol, 5 eq) was added followed by 1,2-dibromoethane (1.53 mL, 17.71 mmol, 1.1 eq) and the suspension was stirred at room temperature for 4 hours. The reaction mixture was then concentrated under reduced pressure and diluted with ethyl acetate. It was washed with saturated aqueous NaHCO3 and brine. The organic layer was dried over Na2SO4 and concentrated under reduced pressure. The crude product was treated with methanol and the solid was filtered and discarded. The mother liquor was evaporated to dryness and purified by chromatography on silica gel (eluant DCM/MeOH 97:3) to give 1.27 g of 3-(7-pyridin-4-yl-2,3-dihydro-pyrazolo[5,1-b]thiazol-6-yl)-benzonitrile as a white solid (26% over 2 steps).

1. concentrationThe reaction mixture was then concentrated under reduced pressure
2. additiondiluted with ethyl acetate
3. washIt was washed with saturated aqueous NaHCO3 and brine
4. dry with materialThe organic layer was dried over Na2SO4
5. concentrationconcentrated under reduced pressure
6. additionThe crude product was treated with methanol
7. filtrationthe solid was filtered
8. customThe mother liquor was evaporated to dryness
9. custompurified by chromatography on silica gel (eluant DCM/MeOH 97:3)