Derivatives of piperazine

Abstract

The preparation of optically active bases will prove conclusively the trihedral distribution of the valencies of trivalent nitrogen. All the aromatic derivatives of this type which have been prepared hitherto have proved to beunsatisfactory for further work. As a preliminary to attempts to prepare bridged compounds from the aliphatic base it was decided to determine the experimental conditions for such preparations with piperazine.A method for the successful preparation of menecarbethexy piperazine has been, worked out. This has made possible the preparation of ether mene N. substituted derivatives of piperazine, and menetolyl sulphonyl, moncethyl, and monoethanol piperazineshave been obtained. Addition compounds of the monosubstituted bases with carbondioxide and carbon bisulphide have been prepared, but the formulation of these compounds, with any certainty is impossible since the properties are such as not to allow of molecular weight dterminations. A quantitative investigation of the metallic derivatives of these pempeunds will probably be of great assist-ance in elucidating the structure of these anomalous substances. Some metallic salts of piperazine diacetic and mono acetic acids have been investigated with a view to comparingtheir internal complex nature with that of analogous salts of other amino acids. The copper, nickel and cabalteus salts of thediacetic acid show nc evidence of internal cemplex formation.Prom piperazine menoacetic acid two isomeric copper salts have been obtained which exibit properties characteristic of internal complex salts. Possible formulae for the salts have been discussed, tentatively, but no final conclusions can yet be drawn.