1,2-Dichloroethane → 3,4-dihydro-6-methoxy-2-[2-[4-(3,4,5-trimethoxybenzoyl)piperazin-1-yl]ethyl]-2,5,7,8-tetramethyl-2H-benzopyran

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Reaction Steps

A solution composed of 2.0 g (6.02 mmol) of the 3,4-dihydro-6-methoxy-2-[2-(piperazin-1-yl)ethyl]-2,5,7,8-tetramethyl-2H-benzopyran obtained by the process of Example 12, 50 ml of 1,2-dichloroethane and 0.57 g of pyridine was ice-cooled in a nitrogen atmosphere and, to this solution, 1.67 g of 3,4,5-trimethoxybenzoyl chloride was added dropwise. The resultant mixture was stirred at room temperature overnight. The reaction mixture was then poured into water and extracted with diethyl ether. The ether layer was dried over anhydrous sodium sulfate. Low-boiling substances were distilled off under reduced pressure and the residue was purified by silica gel column chromatography to give 1.99 g of 3,4-dihydro-6-methoxy-2-[2-[4-(3,4,5-trimethoxybenzoyl)piperazin-1-yl]ethyl]-2,5,7,8-tetramethyl-2H-benzopyran [Compound (17)] having the following physical characteristics.

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