Patent GB-588642-A (GB)
Title: Improvements in manufacture of chlorinated quinones
IPC: C07C50/24
Filed: 1945-02-16
Abstract: Chlorinated quinones are obtained from amino, alkylamino or alkoylamino derivatives of benzene or naphthalene having the respective general formula <FORM:0588642/IV/1> and <FORM:0588642/IV/2> wherein X represents -NH2, -NH-alkyl or -NH.CO-alkyl; Y represents H, -OM, -SO3M (where M represents H or a metal), -NH2, -NH-alkyl, -NH-CO-alkyl, -NO, -NO2, -Cl, -O-alkyl, -CO-alkyl, -N = N-aryl or -COOH; and wherein the 2-, 3-, 5-, 6-, 7- and 8-positions are occupied by hydrogen; chlorine or alkyl (provided at least one such position remains unsubstituted), by chlorination with elemental chlorine in a liquid medium containing sulphuric acid, which may range from a highly diluted to a highly concentrated state, a saturated fatty acid containing from one to four carbon atoms (e.g. acetic, propionic, formic or n-butyric acid) optionally being present.  Chloranil is obtained by the process from aniline, N-methylaniline, N-ethylaniline, acetanilide, p-aminobenzoic acid, p-anisidine, p-phenetidine, p-aminoacetophenone, p-phenylenediamine, p-aminophenol, N-methyl-p-anisidine, p-aminoazobenzene, p-nitraniline, sulphanilic acid, the chloroanilines, the dichloroanilines and 2 : 4 : 6-trichloroaniline; 3 : 5 : 6-trichloro - 2 - methylbenzoquinone is obtained from o- or m-toluidine, and 2 : 3-dichloro-1 : 4-naphthoquinone, from naphthionic acid, a -naphthylamine, 4-nitro - 1 - naphthylamine and 4 - amino - 1 - naphthol.  Amino - benzene compounds are chlorinated in a medium wherein the sulphuric acid concentration may range by weight from 40 to 85 per cent, a preferred mixture consisting of approximately 70 parts of sulphuric acid (96 per cent) and 30 parts of water.  Where the reaction solvent comprises sulphuric and acetic acids, the acetic acid lies between 45 and 75 per cent concentration, a preferred mixture consisting of approximately equal parts of 96 per cent sulphuric acid and glacial acetic acid. The mixture may be diluted with an equal weight of water. Amino-naphthalene compounds are chlorinated in a solvent which may contain from 40 to 60 per cent sulphuric acid for optimum yields, a preferred mixture consisting of approximately equal parts of 96 per cent sulphuric acid and water. Where the reaction solvent comprises sulphuric and acetic acids, it may contain from 5 to 50 parts of sulphuric acid (96 per cent), from 50 to 95 parts of acetic acid and from 0 to 45 parts of water.  The filtrate remaining after removing the product may be utilized instead of the acid mixtures specified.  Chlorination catalysts, e.g. iron, antimony, manganese, or their compounds may optionally be present. The temperature of the reaction-mixture, after the exothermic reaction has subsided, is preferably kept between 80 DEG  and 120 DEG C. In examples: (1) aniline, acetic acid and sulphuric acid are treated in admixture with chlorine substantially at atmospheric pressure, being heated under reflux to 105-115 DEG  C. to obtain chloranil; (2) aniline in aqueous 70 per cent sulphuric acid; (3) aqueous 50 per cent sulphuric acid is treated with chlorine at 110 DEG  C. to obtain chloranil; (4) o-toluidine, sulphuric acid and acetic acid are treated as in (1) to obtain 3 : 5 : 6-trichloro-2-methylbenzoquinone; (5) naphthionic acid, aqueous 50 per cent sulphuric acid and iron powder are treated in admixture with chlorine at 80 DEG  C. to obtain 2 : 3-dichloro-1 : 4-naphthoquinone; (6) the reactants of (5) are chlorinated first at room temperature and then at 90 DEG  C. to obtain the product of (5); (7) sodium naphthionate aqueous 50 per cent sulphuric acid containing crystalline ferrous sulphate is treated with chlorine at room temperature, the temperature being raised to 80 DEG  C., adding more sodium naphthionate, and finally to 90-95 DEG  C. to obtain the product of (5); (8) naphthionic acid, water, acetic acid and 96 per cent sulphuric acid are treated with chlorine at sub-atmospheric temperature, finally heating the mixture at 90-100 DEG  C., to obtain the product of (5); (9) aniline, ice, sulphuric and acetic acid are treated with chlorine at room temperature, prior to boiling, to isolate chloranil; (10) aniline is chlorinated in a mixture of propionic and sulphuric acids, according to (1), to obtain chloranil.