Hydrogen Peroxide → HCID 57998863, compound

Participants

Reaction Conditions

Reaction Steps

Variant A (Oxidation with Hydrogen Peroxide and Iron Sulfate in Water/Acetonitrile): 1-[(Difluoromethyl)sulfonyl]-3-(4,6-dimethoxy-1,3,5-triazin-2-yl)-7-fluoro-1H-indol-2-ol (100 g) is initially charged in 330 ml of acetonitrile and the suspension is heated to 35° C. A solution of potassium hydrogencarbonate (25.4 g) in 145 ml of water is added dropwise within 45 min. Iron(II) sulfate heptahydrate (395 mg) and pyridine-2-carboxylic acid (175 mg) are premixed in 1 ml of water and added to the mixture. Hydrogen peroxide (35% in water, 58 g) is added dropwise over 135 min, and the internal temperature is kept at 25° C.-28° C. Stirring is continued for 170 min, sodium sulfite (3 g) and potassium hydrogencarbonate (3 g) is added, the mixture is concentrated to 282 g at 40° C. under reduced pressure, and the solid residue is filtered off. 2-Propanol (150 ml) is added to the solution and the pH is adjusted to 2 with hydrochloric acid, such that a solid precipitates out. After adding 160 ml of water, the solid is filtered off, washed with 100 ml of 2-propanol/water (1:4) and 200 ml of water, and dried. This gives N-{2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)carbonyl]-6-fluorophenyl}-1,1-difluoromethanesulfonamide in a purity of 97% (86.2 g, 90% of theory).

Provenance & Evidence