Process for the preparation of ortho-aminobenzenesulphonic acids and amino-substituted diphenyl sulfones

摘要

Ortho-aminobenzene sulphonic acids are prepared by reacting a compound of formula FORM:0891815/IV (b)/1 wherein Alk is alkoxy containing 1 to 6 carbon atoms, Ar is aryl, Hal is chlorine or bromine, Al is alkyl containing 1 to 6 carbon atoms; m, o, p, q, r and s are 0 or 1; n is 1 or 2; o+p+q +r+s being 0 or 1 and m+n equals 2, with hydrogen peroxide and sulphuric acid having a strength substantially from 75% to 100%. The same process carried out below 40 DEG C. on compounds of formula FORM:0891815/IV (b)/2 wherein R1, R2, R3 and R4 are hydrogen, bromine or chlorine atoms or nitro, alkyl or alkoxy groups containing 1 to 6 carbon atoms or aryl groups at least one being an amino group yields the corresponding aminodiphenyl sulphones. Compounds prepared in examples are 2 - aminobenzene - sulphonic acid, 2 - amino - 5-methyl- or -amino-benzene-sulphonic acid, 2 - amino - 4 - methoxy- or -chloro- or -phenyl - benzene - sulphonic acid, 4 - amino - 41 - nitro - or - amino - diphenyl sulphone, 2 - amino - 21 - nitro - diphenyl sulphone, 2 - amino - 41 - methyl - diphenyl sulphone, 2 : 21 - diamino - 4 : 41 - dichloro - or - dibromo - diphenyl sulphone and 2 - methoxy - 4 : 41 - diamino - diphenyl sulphone.