RUTHENIUM-CATALYSED REARRENGEMENTS OF AZOBENZENES III. PREPARATION OF N-PHENYL-1,2-PHENYLENEDIAMINE AND N1-PHENYL-N2-(sec-ALKYL)-1,2-PHENYLENEDIAMINE AND DERIVATIVES THEREOF BY THE RUTHENIUM-CATALYSED REACTION OF AZOBENZENES WITH SECONDARY ALCOHOLS

Article abstract of DOI:10.1016/0022-328X(85)88076-1

RuCl3*3H2O in presence of PPh3 and a mild base and under an atmosphere of carbon monoxide catalyses the reaction of azobenzene and 2-propanol to give N-phenyl-1,2-phenylenediamine and N¹-phenyl-N²-(2-propyl)-1,2-phenylenediamine.The selectivity towards the two products can be controlled by varying the amount of base (NaOAc or LiOAc) and 2-propanol used.Secondary alcohols which are less effective for N-alkylation than 2-propanol favour the former product.Substituents in the azobenzene derivative have a marked effect on the yield.Where the azobenzene derivative used permits isomer formation within the N-phenylphenylenediamine unit, all possible isomers usually occur.