Water → 2h-Indazole, 3-chloro-2-(2,4-dichloro-5-(difluoromethoxy)phenyl)-4,5,6,7-tetrahydro-

Participants

Reaction Steps

To a solution of 6.4 g of 3-chloro-2-(2,4-dichloro-5-hydroxyphenyl)-4,5,6,7-tetrahydro-2H-indazole II-1 in 12.5 ml of dioxane were added 12.5 ml of water and 6.4 g of 50% sodium hydroxide. The mixture was heated at 50°~60° C., mixed with excessive amount of chlorodifluoromethane, and heated at 50°~60° C. To the mixture was dropwise added 6.4 g of 50% sodium hydroxide respectively 2.5 hours later and 4 hours later within 15 minutes. The resulting mixture was allowed to react for 2.5 hours, cooled, neutralized, and extracted with ether. The extract was washed with saturated aqueous sodium chloride, dried and concentrated. The residue was purified by silica-gel chromatography to give 4.0 g of the titled compound I-1.

Provenance & Evidence