INDIRECT ELECTROLYSIS INVOLVING AN EX-CELL 2-PHASE PROCESS - REDUCTION OF NITROBENZENES WITH A TITANIUM COMPLEX AS MEDIATOR

Indirect electrolysis of nitrobenzenes, in organic solvent (dichlorome thane, toluene), with a titanium complex (C5H5Ti+ used as mediator in aqueous acidic medium, is performed by phase transfer reaction in a re actor located out of the electrolytic cell. Nitrocompounds are selecti vely reduced to aminoderivatives and the resulting oxidized form of co mplex (C5H5)(2)TiOH+ is reduced at a graphite felt cathode by continuo us recycling of the aqueous solution until the complete reduction of n itrocompounds. Dinitrocompounds are directly reduced to diamino deriva tives. Advantages and limitations of the procedure are shown. Formatio n of an intermediate between the nitrocompound and the reduced form of the mediator is postulated to explain the selectivity of the reductio n. Copyright (C) 1996 Elsevier Science Ltd