Patent GB-980232-A (GB)
Title: Improvements relating to cyclic azo compounds
IPC: C07D285/38
Filed: 1961-07-07
Abstract: 2 - Amino - 4 - methylsulphonyl - 31 - hydroxydiphenyl ether is prepared by reacting 1-chloro-2 - nitrobenzene - 4 - methyl sulphone with resorcin in the presence of sodium carbonate, copper powder and n-amyl alcohol to obtain 2-nitro - 4 - methylsulphonyl - 31 - hydroxydiphenyl ether and reducing the latter in aqueous solution with iron.  2 - Amino - 4 - methylsulphonyl - 31 - dimethylamino-diphenyl ether is obtained similarly using 3 - hydroxy - N,N - diethylaminobenzene instead of resorcin.  2 - Amino - 31 - hydroxy - diphenylthioether is obtained by reacting m-aminothiophenol with o-nitrochlorobenzene, treating the product to obtain the hydrochloride of 2-nitro-31-aminodiphenylthioether, diazotizing the latter, treating with hot aqueous sulphuric acid and reducing the product by catalytic hydrogenation or the B<\>echamp method.  2 - Amino - 4 - methylsulphonyl - 31 - acetylamino-diphenylthioether is obtained by reacting 1 - methylsulphonyl - 3 - nitro - 4 - chlorobenzene with m-aminothiophenol, acetylating the product and reducing with hydrogen and Raney nickel.  The compound of the formula <FORM:0980232/C2/1> is obtained by condensing o-nitrobenzene sulphonic acid chloride and 1-N,N-diethylamino-3-aminobenzene and reducing the nitro compound to the amine by reduction in aqueous/alcoholic solution with iron.  In a further process the intermediate is methylated with methyl sulphate before reduction of the nitro group.  The compounds of the formulae <FORM:0980232/C2/2> and <FORM:0980232/C2/3> are obtained by condensing appropriately substituted benzenes with the appropriate nitrobenzene sulphonic chloride and reducing the nitro group in the product to an amino group.  The compound of the formula <FORM:0980232/C2/4> is obtained by condensing 2-nitrocarboxylic acid chloride with 1-methylamino-3-diethylaminobenzene and reducing the nitro group in the product to an amino group.ALSO:The invention comprises cyclic azo compounds corresponding to the general formula <FORM:0980232/C4-C5/1> wherein R represents the bridging members <FORM:0980232/C4-C5/2> where Y represents hydrogen or a possibly substituted hydrocarbon radical and X represents a secondary or tertiary amino group, a carboxylic acid acylamin, carbonic acid monoester acylamino, a sulphonylamino, hydroxy or alkoxy group and A and B can contain additional substituents and, possibly, fused ring systems, and a process for the preparation thereof comprising diazotizing an o-amino diaryl compound of the general formula <FORM:0980232/C4-C5/3> wherein R, X, Y, A and B have the meanings given above under the condition that the para-position with respect to the substituent X in ring A is unsubstituted, and coupling to form the cyclic compound. Representative of the large numbers of starting materials specified are 2 - amino - 4 - methyl - sulphonyl - 31-hydroxy-; the corresponding 31-methoxy-31-dimethylamino and 31-acetylamino compounds, 1,3 - diamono - 4,6 - bis - (31 - diethylaminophenoxy) 8 benzene, 3,31 - diamino - 4,41-bis - (311 - diethylaminophenyoxy) - diphenylsulphone, 2 - amino - 31 - hydroxy - diphenyl thioether and the corresponding 31-dimethylamino compound 2 - aminobenzene - sulphonic acid or carboxylic acid-N-[31-(N1,N1-dimethyl amino) - phenyl] - N - methylamide.  Additional substituent present in rings A and B may be secondary or tertiary amino groups, carboxylic acylamino, hydroxy or ether groups, carboxylic acid ester or amide or nitrile groups, sulphonic acid and sulphonamide groups, nitro, trifluoromethyl groups and halogen atoms such as fluorine, chlorine or bromine.