Kinetic study of [Ru(SALOPH)Cl₂] complex-catalyzed oxidative carbonylation of methylamine to give methylurethane

Abstract

The oxidative carbonylation of methylamine catalyzed by dichlorobis(salicylaldehyde-o-phenylenediiminatoruthenate(III) at 150°C and CO + O2 (1:0.5) pressure of 21 atm gave methylurethane (80%), dimethylurea (15%) and N-methylformamide (5%) as the reaction products, with a turnover rate of 40 mol products per mole catalyst per hour. The rates of oxidative carbonylation measured at 150°C and in the pressure range 5-21 atm, exhibited a first-order dependence with respect to catalyst, substrate and dissolved CO concentrations, while it was half-order with respect to dissolved O₂ concentration. An activation energy of 9.2 kcal mol⁻¹ was estimated from the measurements of rates of oxidative carbonylation of methylamine in the temperature range 150-170°C.