Water → 4-Cyclopropyl-5,7-difluoro-3,4-dihydro-2H-chromen-4-ol

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Reaction Conditions

Reaction Steps

2.00 g (10.86 mmol) of the compound from Example 170A were dissolved in 40 ml of diethyl ether at 0° C., and 32.6 ml (16.29 mmol) of a 0.5N solution of cyclopropylmagnesium bromide in tetrahydrofuran were slowly added dropwise. Stirring at 0° C. for 1 h was followed by warming to RT, addition of water and diethyl ether to the reaction solution and separation of the phases. The aqueous phase was extracted with diethyl ether, and the combined organic phases were dried over sodium sulfate and filtered, and the solvents were removed in vacuo. The crude product was purified by preparative HPLC (mobile phase: acetonitrile/water gradient). The acetonitrile was removed from the combined product phases in a rotary evaporator, and the aqueous phase was extracted with dichloromethane. The combined organic phases were dried over sodium sulfate and filtered, and the solvents were removed in vacuo. 0.66 g (27% of theory) of the title compound was obtained.

Provenance & Evidence