Реакция #42745

Уравнение реакции

trifluoromethanesulfonic acid anhydride

sodium 3-(4-chlorophenyl)-2-isopropyl-8-methoxy-4-oxo-4H-chromen-7-olate

3-(4-chlorophenyl)-7-hydroxy-2-isopropyl-8-methoxy-chromen-4-one

sodium hydride

pyridine

→

title compound

Trifluoromethanesulfonic acid 3-(4-chlorophenyl)-2-isopropyl-8-methoxy-4-oxo-4H-chromen-7-yl ester

Растворители

methylene chloride

tetrahydrofuran

methylene chloride

Условия реакции

Обработка

1. 1
   Другоеprepared
2. 2
   Промывкаthe solution is washed with 1M HCl solution
3. 3
   СушкаThe organic phase is dried over anhydrous magnesium sulfate
4. 4
   Фильтрацияfiltered
5. 5
   Другоеthe solvent is removed by evaporation in vacuo

Методика

A solution of trifluoromethanesulfonic acid anhydride (3.5 g, 2.1 ml, 12.4 mmol, 2 eq.) in anhydrous methylene chloride (10 ml) is added dropwise to a stirred solution of sodium 3-(4-chlorophenyl)-2-isopropyl-8-methoxy-4-oxo-4H-chromen-7-olate (2.28 g, 6.22 mmol; prepared by treating 3-(4-chlorophenyl)-7-hydroxy-2-isopropyl-8-methoxy-chromen-4-one with a molar equivalent of sodium hydride in dry tetrahydrofuran), pyridine (2 g, 2.1 ml, 25.5 mmol, 4.1 eq.) and 4-dimethylaminopyridine (0.076 g, 0.62 mmol, 0.1 eq.) in anhydrous methylene chloride (60 ml) at 0° C. After stirring overnight, the solution is washed with 1M HCl solution. The organic phase is dried over anhydrous magnesium sulfate and filtered, and the solvent is removed by evaporation in vacuo to afford the title compound as a brown foam. The product is used in the next step without further purification.

Источник