1-Naphthalenesulfonamide, 5,8-dihydro-5,8-dioxo- synthesis

Yield:1309647-27-5 58.43%

Reaction Conditions:

with cerium(IV) sulphate;sulfuric acid;acetic acid in water at 65; for 0.45 h;

Steps:

2). Preparation of 5,8-dioxo-dihydronaphthalene

Dissolve anhydrous cerium sulfate (160g, 677.45mmol) with 750ml 2mol/L dilute sulfuric acid,The temperature is controlled at 65°C. Add 1-naphthalenesulfonamide (10g, 48.49mmol) into a 500ml round bottom flask containing 200ml of glacial acetic acid, control the temperature at 65°C, and stir at this temperature.Slowly add dropwise to the cerium sulfate aqueous system, start timing from the dropwise addition,Monitoring by thin layer chromatography, the reaction was stopped after 27 minutes, and after the reaction solution was cooled, Filter, extract the filtrate with 1200ml of dichloromethane, dry and remove water, and then rotate under low pressure.A light yellow solid was obtained, which was dried under vacuum,5,8-dioxo-dihydronaphthalene (6.72 g, yield 58.43%) was obtained. It is directly used in the next reaction without purification.

References:

CN112920136,2021,A Location in patent:Paragraph 0063-0066