Toluene → ethyl 2,2-bisfluoromethyl-6-trifluoromethyl-2H-1-benzopyran-4-carboxylate

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Reaction Conditions

Reaction Steps

A mixture of 1.00 g of 2,2-bisfluoromethyl-6-iodo-2H-1-benzopyran-4-carboxylic acid ethyl ester, 0.84 g of potassium trifluoroacetate, 1.18 g of cuprous iodide, 4 ml of toluene and 10 ml of N,N-dimethylformamide was stirred with heating at 150° C. for 5.5 hours under a nitrogen gas atmosphere while removing toluene. The reaction mixture was combined with a mixture of 2N hydrochloric acid and ethyl acetate, and unsoluble matters were filtered out with Celite. Organic layers were collected from the filtrate and the aqueous layer was extracted with ethyl acetate. The organic layers were combined and washed with saturated saline, dried over sodium sulfate, then concentrated under reduced pressure, and the resulting residue was subjected to silica gel chromatography (eluent: ethyl acetate:hexane=10:1) to give 0.51 g of 2,2-bisfluoromethyl-6-trifluoromethyl-2H-1-benzopyran-4-carboxylic acid ethyl ester as an oil;

Provenance & Evidence