GB468648A - Manufacture of vat-dyestuffs and intermediates - Google Patents

Abstract

Vat dyes or intermediates are made by heating fluoranthene with an o-dicarboxylic acid anhydride in presence of a condensing agent, at least 2\ba1/2\be mols. of the anhydride being used for each mol. of fluoranthene. The product may be halogenated. The process may be carried out in one stage, or by using first 1 mol. of the anhydride for 1 mol. fluoranthene to produce a monoketone-carboxylic acid or a corresponding diketone, and condensing the latter with at least 1\ba1/2\be mols. of the anhydride. Suitable condensing agents are aluminium halides such as aluminium chloride or ferric chloride; these condensing agents may be used in presence of an alkali halide, such as sodium or potassium chlorides or both, or of a solvent or dispersing agent such as benzene, trichlorbenzene, chlornaphthalene, or nitrobenzene. The products may be converted to their leuco derivatives, such as their leuco-sulphuric acid esters, and are in part dyestuffs dyeing cotton strong reddish-yellow shades and dyeing and printing vegetable fibres, and in part intermediates. In examples, fluoranthene and monophthaloylfluoranthene are each melted with phthalic anhydride and aluminium chloride, and the product obtained from fluoranthene is chlorinated, using sulphuryl chloride, or brominated, and in another example, vatted and used to dye cotton. Specification 378,476 is referred to.