反应详情

A mixture of 2-(2-methylpyrazolo[1,5-a]pyridin-3-yl)-4-phenyl-1,3-thiazole-5-carboxamide (200 mg, 0.6 mmol) produced in the above and N,N-dimethylformamide dimethyl acetal (5 mL) was stirred at 100° C. for 2 hr. The reaction mixture was concentrated under reduced pressure, hydrazine monohydrate (0.29 mL, 6.0 mmol) and acetic acid (10 mL) were added to the obtained residue, and the mixture was stirred at 100° C. for 2 hr. The reaction mixture was concentrated under reduced pressure, and aqueous sodium bicarbonate solution and diethyl ether were added to the obtained residue. The resulting precipitate was collected by filtration, washed with water and diethyl ether and dried to give 2-methyl-3-[4-phenyl-5-(4H-1,2,4-triazol-3-yl)-1,3-thiazol-2-yl]pyrazolo[1,5-a]pyridine (210 mg, 98%) as a pale-yellow solid. The obtained 2-methyl-3-[4-phenyl-5-(4H-1,2,4-triazol-3-yl)-1,3-thiazol-2-yl]pyrazolo[1,5-a]pyridine (90 mg, 0.25 mmol) and p-toluenesulfonic acid monohydrate (57 mg, 0.3 mmol) were dissolved in ethanol (6 mL) by heating, and the mixture was concentrated under reduced pressure. The obtained residue was crystallized from ethanol and ethyl acetate to give the title compound (93 mg, 70%) as a pale-orange solid.

1. temperatureby heating
2. concentrationthe mixture was concentrated under reduced pressure
3. customThe obtained residue was crystallized from ethanol and ethyl acetate