反应详情

A solution of 5-benzoyl-4-hydroxy-2-methoxybenzenesulfonic acid (Uvinul MS-40, a product of BASF Wyandotte Corporation) (20.0g, 0.065 mole) and 250 ml of warm tetrahydrofuran was cooled to room temperature. A solution of 8.0g (0.10 mole) of pyridine in 25 ml tetrahydrofuran was added accompanied by an exotherm. The resulting mixture was stirred at room temperature for 30 minutes, then poured into 200 ml pentane and stirred briefly before the sulfonic acid salt (23.5g) was collected by filtration. This salt was added slowly over 15 minutes to 29.0g (0.244 mole) of thionyl chloride at 50° C. under a nitrogen atmosphere. The resulting mixture was stirred at 55° C. for 1 hour 45 minutes. The reaction mixture was poured into 600 ml of ice water to precipitate the product. The product was isolated by filtration and transferred to a separatory funnel with 200 ml chloroform. The mixture was extracted with 125 ml of 2.5 % HCl, 100 ml of 2.5% HCl and 100 ml water. The organic phase was dried with anhydrous magnesium sulfate and stripped of solvent using aspirator and high vacuum systems. The product weighed 16.5g and melted at 165°-172° C.

1. filtrationwas collected by filtration
2. stirringThe resulting mixture was stirred at 55° C. for 1 hour 45 minutes
3. customto precipitate the product
4. customThe product was isolated by filtration
5. extractionThe mixture was extracted with 125 ml of 2.5 % HCl, 100 ml of 2.5% HCl and 100 ml water
6. dry with materialThe organic phase was dried with anhydrous magnesium sulfate