Triethylamine → 8-{2-[4-(2-Methoxyphenyl)-1-piperazinyl]ethylsulfonylamino}-3-methyl-4-oxo-2-phenyl-4H-1-benzopyran methanesulfonate

Participants

Reaction Conditions

Reaction Steps

1.05 ml of 2-chloroethanesulfonyl chloride was added dropwise to a solution of 5 g of 8-amino-3-methyl-4-oxo-2-phenyl-4H-1-benzopyran and 1.4 ml of triethylamine stirred at 0° C. The reaction mixture was stirred at room temperature for 2 days. After filtering the precipitated solid, the solution was evaporated to dryness in vacuo to give a crude residue containing 8-(ethenYlsulfonylamino)-3-methyl-4-oxo-2-phenyl-4H-1-benzopyran used without further purification. A mixture of 7.54 g of this residue and 5.8 g of 1-(2-methoxyphenyl)piperazine and 4.15 g of potassium carbonate in 100 ml of dimethylformamide was stirred at room temperature for 4 hours, poured into 600 ml of water and extracted with ethyl acetate. The organic layer was evaporated to dryness in vacuo and the residue was purified-by column chromatography on silica gel eluting with petroleum ether-acetone 8:2. The collected fractions were evaporated to dryness in vacuo and crystallized from 70% ethanol to give 0.75 g of the title compound as a base. This solid was dissolved in dichloromethane and 1 equivalent of methanesulfonic acid was added to the solution. The crude methanesulfonate, obtained by evaporation in vacuo, was crystallized from acetone, yielding 0.6 g of the title compound melting at 202°-203° C.

Provenance & Evidence