Sodium Carbonate → 5-(3,4-dihydro-2H-1-benzopyran-6-yl)-1,3-dimethyl-1H-pyrazole-4-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

A solution of 5-chloro-1,3-dimethyl-1H-pyrazole-4-carboxaldehyde (200 mg, 1.26 mmol), sodium carbonate (282 mg, 2.66 mmol), 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)chroman (426 mg, 1.64 mmol) and palladium tetrakis(triphenylphosphine) (73 mg, 0.063 mmol) in a mixture of dimethoxyethane (4 mL) and water (1.35 mL) was heated at 85° C. for 24 hours. After cooling to room temperature, the mixture was poured into water (10 mL). The aqueous layer was extracted with ethyl acetate (2×10 mL). The organic layer was washed with brine (10 mL), dried over sodium sulfate and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (cyclohexane/ethyl acetate 80/20 then 50/50) to provide the desired product (27a) (110 mg, 0.43 mmol, 34%) as a beige solid.

Provenance & Evidence