Novel terms of benzene-1,2-diamine propargylation

A novel method of benzene-1,2-diamine propargylation in benzene in the presence of potassium carbonate and tetra-n-butyl ammonium iodide as organic catalyst helps to produce N-(prop-2-yn-1-yl)benzene-1,2-diamine in 83 % yield, Simultaneously N,N1-di(prop-2-yn-1-yl)benzene-1,2-diamine is formed in 7 % yield. Propargylation in benzene has been carried out at molar relation of benzene-1,2-diamine reagents: propargyl bromide: potash: n-Bu4NI = 1:1:0,5:0,05. In comparison with earlier known method a yield of N-(prop-2-yn-1-yl)benzene-1,2-diamine has a double increase, the time needed to carry out the whole reaction is ten time less in comparison to the previously described method. When analogical reaction of benzene-1,2-diamine is held in a mixture of methyl cyanide and ethanol (2:1) at molar relation of reagents 1:2:1:0,1, three amines are obtained: symmetrically substituted N,N1-di(prop-2-yn-1-yl)benzene-1,2-diamine, asymmetrically substituted N,N-di(prop-2-yn-1-yl)benzene-1,2-diamine and N,N,N1-tri(prop-2-yn-1-yl)benzene-1,2-diamine in a proportion 2:1:4 in a 55 % overall yield. Column chromatography on silica by benzene elution helps to obtain samples of all individual amines. IR, NMR 1H, 13C, mass-spectra confirm their structures.