反应详情

Compound 2a (1.03 g, 5.0 mmol) prepared in Step 1 of Example A-1 was charged in a 25 mL round-bottom flask and dissolved in 6 mL of ethanol. A solution of 2-hydrazinopyridine (0.55 g, 5.0 mmol, manufactured by Aldrich) in 5 mL of ethanol at 50° C. was gradually added thereto over 30 minutes, followed by reaction for 1 hour. After completion of the reaction was confirmed by TLC, the reaction solution was concentrated by evaporation, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous sodium sulfate, concentrated, and then purified by column chromatography [n-Hex/EtOAc=3/1 (v/v)] to afford a compound of 3-benzyl-1-(pyridin-2-yl)-1H-pyrazol-5-ol (3a).

1. customfollowed by reaction for 1 hour
2. concentrationthe reaction solution was concentrated by evaporation
3. extractionextracted with ethyl acetate
4. washwashed with saturated brine
5. dry with materialdried over anhydrous sodium sulfate
6. concentrationconcentrated
7. custompurified by column chromatography [n-Hex/EtOAc=3/1 (v/v)]