反应详情

To a solution of ethyl 3-iodo-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole-4-carboxylate (5 g, 14.2 mmol) in (1:1) THF/MeOH (32 mL) was added a solution of LiOH (1.8 g, 4.28 mmol) in water (16 mL). The reaction was stirred at rt for 4 h then evaporated under vacuum and the residue was treated with water (25 mL) and washed with ethyl acetate (30 mL×2). The aqueous layer was isolated acidified to ˜pH5 with 2N HCl and extracted with DCM (30 mL×3). The combined extracts were washed with brine (30 mL), dried and concentrated to afford 3-iodo-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole-4-carboxylic acid (3.5 g, yield: 76%). LCMS (method B): RT=2.18 min, m/z=321.0 [M−H]−.

1. customthen evaporated under vacuum
2. additionthe residue was treated with water (25 mL)
3. washwashed with ethyl acetate (30 mL×2)
4. customThe aqueous layer was isolated
5. extractionextracted with DCM (30 mL×3)
6. washThe combined extracts were washed with brine (30 mL)
7. customdried
8. concentrationconcentrated