Hydrochloric Acid → 3-Iodo-1-(tetrahydro-pyran-2-yl)-1H-pyrazole-4-carboxylic acid

関与物質

反応手順

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]−.

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