Oxidative carbonylation of cyclohexylamine to cyclohexylurethane catalyzed by dichlorobis-(salicylaldehyde)-o-phenylenediiminato ruthenate(III)

Abstract

The complex [Ru(saloph)Cl2] (saloph = bis-(salicylaldehyde)-o-phenylenediimine) catalyses the oxidative carbonylation of cyclohexylamine in ethanol medium to cyclohexylurethane selectively at 160“C and CO + O2 (1:0.50) pressure of 21 atm. A turnover number of 30 mol per mol catalyst per hour was observed in this reaction. The rate of oxidative carbonylation of cyclohexylamine measured at 160“C in the range 7-21 atm is first order with respect to catalyst, cyclohexylamine and dissolved CO concentrations and one-half order with respect to dissolved O2 concentration. The effect of temperature on the rate of oxidative carbonylation was studied in the temperature range 150-170°C and the activation energy evaluated as 21.0 kcal mol-l.