Dimethyl Sulfate → 4-methoxy-3-[3-[3-(2-cyanoethenyl)phenyl]-1-oxo-2-propenyl]-6-methyl-2H-pyran-2-one

Participants

Reaction Conditions

Reaction Steps

To a mixture of 20 ml of hexamethylphosphoramide and 3.50 g of 4-hydroxy-3-[3-[3-(2-cyanoethenyl)phenyl]-1-oxo-2-propenyl]-6-methyl-2H-pyran-2-one was added 0.46 g of sodium hydride (60% oily) at about 0° C., and a temperature was raised to 50° C., followed by stirring for 1 hour and 10 minutes. Then, 3.22 g of dimethyl sulfate was added thereto, and the mixture was stirred at 50° C. for 4 hours. Thereafter, the reaction mixture was added to ice water, and the mixture was extracted with ethyl acetate. The organic layer washed with an aqueous saturated sodium chloride solution, dried over anhydrous magnesium sulfate, and concentrated. The residue was subjected to silica gel column chromatography to obtain 1.12 g of 4-methoxy-3-[3-[3-(2-cyanoethenyl)phenyl]-1-oxo-2-propenyl]-6-methyl-2H-pyran-2-one [Compound No. (2a)] as a pale yellow crystal.

Provenance & Evidence