Sodium Hydroxide → Apararenone

Participants

Reaction Steps

To a suspension of N-[4-(4-fluorophenyl)-2,2-dimethyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-7-yl]-N-(methylsulfonyl)methanesulfonamide (1 g) in isopropanol (3 mL) was added dropwise an aqueous sodium hydroxide solution (0.18 g/3 mL) at 25° C., then isopropanol/water (1:1.2 mL) was added thereto, and the mixture was stirred overnight at the same temperature. To the reaction mixture was added dropwise concentrated hydrochloric acid/isopropanol/water (0.24 g/0.5 mL/0.35 mL) at 25° C., and the mixture was stirred for 1 hour. The precipitated crystals were collected by filtration, washed with a solution of isopropanol/water (1:1.6 mL), and then dried under reduced pressure at 50° C. to obtain the title compound (0.78 g) as Form D crystals (yield: 94%, purity: 99%).

Provenance & Evidence