Methyl iodide → 7-methoxy-2,2-dimethyl-3,4-dihydro-2H-1-benzopyran-4-one

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Reaction Steps

In 40 ml of 5% sodium hydroxide solution 3.84 g (20 millimoles) of 7-hydroxy-2,2-dimethyl-4-chromanone are dissolved whereupon 80 ml of dichloro methane and 0.5 g of triethyl benzyl ammonium chloride are added and the mixture is intensively stirred at room temperature for 20 minutes. After addition of 4.25 g (1.9 ml, 30 millimole) of methyl iodide the reaction mixture is stirred for 2 hours. The organic layer is separated, washed twice with 50 ml of water each, dried over sodium sulfate and evaporated. The residue is crystallized from 80% methanol. Thus 3.9 g of the desired compound are obtained, yield 94.6%. Mp. 77°-78° C.

Provenance & Evidence