Hydrogen Peroxide → Crystal Violet lactone

Participants

Reaction Conditions

Reaction Steps

To 1,500 wt. parts of an aqueous solution containing 41.7 wt. parts of 2-[4,4'-bis-(dimethylamino)-benzhydryl]-5-dimethylaminobenzoic acid and 4.4 wt. parts of sodium hydroxide was added 0.4 wt. part of cobaltous chloride. The mixture was heated at 70° C. and 51 wt. parts of 10% aqueous solution of hydrogen peroxide was added dropwise during 1 hour (pH=9.9). The precipitate was separated and dissolved into toluene and the catalyst was separated by a filtration and toluene was distilled off to obtain 39.8 wt. parts of 3,3-bis-(4-dimethylaminophenyl)-6-dimethylaminophthalide having a melting point of 180° to 183° C.

Provenance & Evidence