GB208720A - The manufacture of a dyestuff from naphthidine - Google Patents

Abstract

3.10-Perylene quinone is prepared by heating 4.41-diamino-1.11-dinaphthyl (naphthidine) or a salt thereof with a ring-closing condensing agent and oxidizing the 3.10-diaminoperylene formed, with or without previous isolation. Ring-closing condensing agents mentioned are aluminium chloride and ferric chloride, to which an alkali salt may be added. The quinone may be purified by treatment with a solvent such as pyridine, or it is vatted and again oxidized. According to the example, naphthidine is heated with aluminium chloride; the product is pulverized, washed with dilute hydrochloric acid, and oxidized with a mixture of sodium bichromate and sulphuric acid; the residue forms a red vat from which the quinone is precipitated on oxidation. It dyes cotton yellow. The Specification as open to inspection under Sect. 91 (3) (a) describes also the preparation of 3.10-perylene quinone by dissolving 3.10-diaminoperylene in concentrated sulphuric acid and treating it with nitrous acid. By chlorinating a suspension of 3.10-perylene quinone in nitrobenzene, a chloro derivative is produced which dyes a vivid yellow from a red vat. The corresponding bromo derivative dyes orange. It is stated that nitro, amino, anilido and other derivatives may also be produced. This subject-matter does not appear in the Specification as accepted.