Collect. Czech. Chem. Commun. 1981, 46, 92-100

Mechanism of the Ullmann condensation

Zdeněk Vrba

Research Institute of Organic Syntheses, 532 18 Pardubice-Rybitví


It has been found that the condensation rate of 1-amino-4-bromoanthraquinone-2-sulphonic acid (I) with 1,3-diaminobenzene-4-sulphonic acid (II) giving 1-amino-4-(3'-amino-4'-sulphoanilino)anthraquinone-2-sulphonic acid (III) in media of NaHCO3-CO2 and NaHCO3-Na2CO3 with catalysis by CuI obeys the kinetic relation *u = k[I][II][Cu+][CO2-3], being controlled by the kinetic relation *u = k[I][II][Cu+]2[PO3-4] in media of NaH2PO4-Na2HPO4 buffers. The suggested reaction mechanism presumes formation of a bifunctional catalyst CuCO-3 or Cu2PO-4 which splits off the proton and bromide anion from the reaction intermediate in the rate-limiting step.