KINETICS OF THE FORMATION OF THE HERBICIDE PHENMEDIPHAN

The rate of formation of 3-methoxycarbonylaminophe-nyl-N-3-tolylcarbam ate (I) by addition of methyl-N-(3-hydroxyphenyl)-carbamate III to 3-t olylisocyanate (IV) in toluene was determined under catalysis with tri ethylamine. From kinetic experiments at 67-degrees-C it was found that the reaction is a 1st order one with respect to both components and t he bimolecular rate constant is linearly dependent on the concentratio n of triethylamine. The overall reaction rate is defined by the kineti c equation v = k3[III] [IV] [(C2H5)3N] where k3 = 256 +/- 15 dm6 mol-2 min-1.