Collect. Czech. Chem. Commun. 1980, 45, 2334-2342

Kinetics of reactions of acyl isothiocyanates with amines

Ján Imrich, Pavol Kristian, Dušan Podhradský and Milan Dzurilla

Department of Organic Chemistry, P. J. Šafárik University, 041 67 Košice


The kinetics of reactions of 4-substituted benzoyl, cinnamoyl and phenyl isothiocyanates with aliphatic amines and glycine ethyl ester in organic solvents was studied by the stopped-flow and UV spectroscopic methods. The reaction of acyl isothiocyanates with the nucleophilic reagents employed proved to be 103 - 104 times faster than analogous reaction of phenyl isothiocyanates. A linear correlation between logk and σp constants with positive ρ slope was found. The solvent polarity has only a negligible effect on the reaction. UV spectra as well as gas chromatography of the reaction products proved that under the employed experimental conditions N,N'-disubstituted thioureas are the sole reaction products.