4-Sulfophthalic acid → Phthaloperinone sulphochloride

Participants

Reaction Conditions

Reaction Steps

11.5 g of sulphophthaloperinone, prepared from 4-sulphophthalic acid and 1,8-naphthylenediamine in N-methylpyrrolidone, are suspended in 100 ml of xylene. 9.2 g of phosphorus oxychloride are added and the mixture is heated to 80° C for 6 - 7 hours, whilst stirring. 25 - 30 ml of xylene are then distilled off under reduced pressure and after cooling the reaction product which has precipitated is filtered off and the residue is rinsed with petroleum ether. 11.6 g of phthaloperinone-sulphochloride are obtained.

Provenance & Evidence