Synthesis and properties of phenyl substituted derivatives of 2-phenyl-1,1,3,3-tetramethylguanidine

Abstract

A series of 17 phenyl substituted derivatives of 2-phenyl-l,l,3,3-tetrarnethylguanidinew as synthesized. The structure and purity of these compounds were checked by means of elemental analyses, mass spectrometry, ultraviolet spectrophotornetry, and 1H nuclear magnetic resonance. The pKa, values were determined and arediscussed in terms of substituent effects using Hammett substituent constants. The Harnrnett reaction constant p = 1.84 ± 0.05 was found to be much lower for para and meta substituted compounds than for anilines, even though the phenyl ring is attached directly to the basic centre in both cases.