Bayer Aktiengesellschaft

Uwe Heinz

Heinz U Blank

Helmut Fiege

Horst Behre

Heinz-Ulrich Blank

Wolfgang Eymann

4,6-diaminoresorcinol can be prepared in a plurality of steps in such a way that a) 1,3-dichlorobenzene is nitrated with a mixed acid of HNO.sub.3, H.sub.2 SO.sub.4 and SO.sub.3 at 0 to 40.degree. C. in anhydrous H.sub.2 SO.sub.4, b) the resulting 1,3-dichloro-4,6/2,4-dinitrobenzene isomeric mixture is first reacted with benzyl alcohol in the presence of a strong base at -15.degree. C. to +15.degree. C. and then at 20.degree. to 40.degree. C. to give the dibenzyloxy compound and c) the 1,3-dibenzyloxy-4,6-dinitrobenzene isomer arising in pure form in b) is converted to the 4,6-diaminoresorcinol by catalytic hydrogenation.

Process for the preparation of 4,6-diaminoresorcinol

Aromatic (di)chlorosulphonic acids and (di)bromosulphonic acids can be prepared by reacting aromatic sulphonic acids with chlorine or bromine respectively, the reaction advantageously being carried out in the melt of the aromatic sulphonic acids.

Process for the preparation of aromatic (di)chlorosulphonic acids and

The new 1,3-di-arylmethoxy-4,6-dinitrobenzenes of the formula ##STR1## in which R.sup.1 and R.sup.2 independently of one another denote hydrogen or C.sub.1 -C.sub.4 -alkyl and

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Cologne, Germany

Uwe Heinz