511,353. Phenanthridine compounds dyes. MORGAN, SIR G. T., and WALLS, L. P. Jan. 13, 1938, Nos. 1123 and 29037. [Class 2 (iii)] Aminophenanthridines are prepared by reducing a phenanthridine compound obtainable by ring closure, in the presence of a pentavalent phosphorus compound, of an acylated o-xenylamine containing more than one nitro group. The products may be converted into their quarternary salts by treatment. with an alkylating agent, or they may first be acylated and then converted with alkylating agents into their quaternary salts. Alternatively, the phenanthridine compound, obtainable by ring closure of the acylated o-xenylamine, is first treated with an alkylating agent and then reduced. The acyl groups may be split off by hydrolysis. The quaternary salts are useful therapeutically, whilst some of them have dyeing properties. According to the examples, (1) 5-nitro-2- xenylamine is condensed with p-nitrobenzoyl chloride and ring closure effected with phosphorus oxychloride to 3-nitro-9-p-nitrophenylphenanthridine ; reduction with hydrogen under pressure using a platinic oxide catalyst gives. the diamino compound, from which a diacetyl compound is prepared ; from the latter, by treatment with methyl p-toluenesulphonate and salting out with sodium chloride, a quaternary chloride is obtained which, by hydrolysis, yields 3-amino-9-p-aminophenyl-10-methylphenanthridinium chloride ; similarly, starting with 4<1>-nitro-2-xenylamine, 7-amino-9-paminophenyl-10-methylphenanthridinium chloride is' obtained ; (2) 4<1>-nitro-2-p-nitrobenzamidodiphenyl is heated in nitrobenzene with phosphorus oxychloride and the resulting 7-nitro-9- p-nitrophenylphenanthridine, after conversion into its methosulphate, reduced with iron and acidified water to the diamino compound, which can be diacetylated ; the methosulphate may be treated with alkali and the precipitated pseudobase converted into its chloride, which can then be subjected to the reduction and acetylation treatment; (3) 3:5-dinitrobenzoyl-o-xenylamine obtained by condensing o-xenylamine with 3:5-dinitrobenzoyl chloride, is cyclised with phosphorus oxychloride, the 3<1>:5<1>-dinitrophenyl-9-phenanthridine so formed converted into its methosulphate and then by salting out into the quaternary chloride, which is reduced with stannous chloride to 3:5<1>-diaminophenyl-9- phenanthridinium methochloride; (4) 3:7- dinitro-9-phenylphenanthridine is first prepared by ring closure of 5-4<1>-dinitro-2-benzamidodiphenyl, obtained from benzoic anhydride and 5:4<1>-dinitro-o-xenylamine, by means of phosphorus oxychloride ; by reduction with hydrogen in an autoclave, acetylation of the product and treatment as in (1), 3:7-diacetamido-9- phenyl-10-methylphenanthridinium chloride is obtained, which may be hydrolysed to the diamino-quaternary chloride ; alternatively, the dinitro compound is converted into the said quaternary salt by way of 3:7-dinitro-9-phenyl- 10-methylphenanthridinium chloride; (5) 41- nitro-2-acetamidodiphenyl is brominated, the product hydrolysed and condensed with p-nitrobenzoyl chloride to yield 5-bromo-4<1>-nitro-2- p-nitrobenzamidodiphenyl; this is subjected to ring closure, the resulting 3-bromo-7-nitro-9- p-nitrophenylphenanthridine reduced with stannous chloride, the diamino compound acetylated, and then converted into its quarternary salt 3-bromo-7-amino-9-p-aminophenyl- 10-methylphenanthridinium chloride ; (6) 41- nitro-2-aminodiphenyl is condensed with 3:5- dinitrobenzoyl chloride, the 4<1>-nitro-2:3<11>-5<11>- dinitrobenzamidodiphenyl cyclised to -7nitro- 31-51-dinitrophenyl-9-phenanthridine, which is then.reduced with hydrogen in an autoclave and converted into its triacetyl derivative. Specification 372,859 is referred to.