Patent GB-508029-A (GB)
Abstract: 508,029. Dyes and intermediates. 1. G. FARBENINDUSTRIE AKT. - GES. Dec. 23, 1937, No. 35677. Convention date, Dec. 24, 1936. [Class 2 (iii)] Benzanthrone derivatives are manufactured by reacting a Bz1-alkoxybenzanthrone, or a Bz2- carboxylic acid or ester thereof, with a primary aromatic amine, which may be a vattable compound, in the presence of a caustic alkali, the ester group when present being saponified during the reaction. Suitable aromatic amines are those of the benzene, naphthalene, benzanthrone and anthraquinone series, which may contain further substituents such as halogen atoms, alkyl or alkoxy groups. The reaction is preferably carried out in the presence of an indifferent solvent, e.g. pyridine, mono- or dimethylaniline or quinoline, or of excess of the aromatic amine as solvent. Depending on conditions, there are obtained Bzl-arylaminobenzanthrones or the benzanthrone-hydroacridines resulting from ring closure thereof, the former being capable of transformation into the latter by melting with caustic alkali. The products are dyestuffs or intermediates therefor. In examples : (1) Bzl-methoxybenzanthrone is heated'with aniline in the presence of caustic potash and pyridine, yielding Bzl-anilidobenzanthrone ; the pyridine may be replaced by quinoline, mono- or dimethylaniline or an excess of aniline ; (2) p-toluidine similarly yields Bzl-p-toluidobenzanthrone ; (3) Bzlethoxybenzanthrone is heated with o-chloraniline in the presence of caustic potash to produce Bzl-o-chloranilidobenzanthrone ; (4) Bzl-methoxybenzanthrone is reacted with oanisidine by the process of (1) to yield Bzl-omethoxyanilidobenzanthrone ; (5) #-naphthylamine similarly yields Bz1-#-naphthylaminobenzanthrone ; (6) the reaction of (5) is carried out at a higher temperature, using excess of #-naphthylamine in place of pyridine, whereby the corresponding hydroacridine is formed ; (7) Bzl-methoxybenzanthrone is heated with Bzl-aminobenzanthrone in the presence of caustic potash and pyridine, producing Bzl- Bz<1>l<1>-dibenzanthronylamine ; (8) Bz1-methoxybenzanthrone is heated with Bz2-aminobenzanthrone in the presence of caustic potash and pyridine to produce Bzl-Bz<1>2<1>-dibenzanthronylamine ; by fusing this with caustic potash and alcohol there is obtained the corresponding hydroacridine, which dyes cotton violet shades from a bluish-red vat ; (9) #- aminoanthraquinone similarly yields Bzl-benzanthronyl - 2 - anthraquinonylamine and the corresponding hydroacridine ; the latter may be treated with p-toluenesulphonic acid methyl ester in nitrobenzene in the presence of potassium carbonate to produce the N-methyl compound, which dyes cotton olive greenish grey shades from a reddish-brown vat; 2-amino- 3-chloroanthraquinone may be employed in a similar series of reactions ; (10) Bzl-methoxybenzanthrone is heated with alpha-aminoanthraquinone in the preseiice of caustic potash and pyridine, yielding Bz1-benzanthronyl-1-aminoanthraquinone and, by the action of an alcoholic potash melt, the corresponding hydroacridine ; (11) Bz1 - methoxybenzanthrone - Bz2 - carboxylic acid methyl ester is heated with 2 : 4- dichloraniline in the presence of caustic potash and pyridine, producing Bzl-(2' : 4<1>-dichlor.- anilido(-benzanthrone-Bz-2-carboxylic acid ; (12) with alpha-aminoanthraquinone there is similarly obtained a hydroacridine, which yields olive green dyeings from a violetblue vat.