1818
RAY
h.cL.4RKE
AND BERTE. CHRISTENSEN
Vol. 70
TABLE I YIELDSO F PIPERAZINE UNDER VARIOUS REACTION CONDITIONS Temperature, OC.
Reagent
G.
Solvent
Diethylenetriarnine Diethylenetriamine Diethy lenetriamine Diethylenetriamine Diethylenetriamine Diethylenetriamine Ethylenediamine
103
None Tetrahydronaphthalene None Dipentene Xylene Dioxane Tetrahydronaphthalene
60
2HsNCH~CHzNH~ +H-Ii
CH+2H2-NHg
Yjdd of p!peram e , g.
Yield
46 53 33 63 1s 28 17
53 62 38 73 17 32 39
10 12
8 8 7 7 6
%
which was first refluxed with sodium and aniline and then distilled. In each of the reactions listed in Table I, 10 g. of Raney nickel was used. The reaction mixture was fractionally distilled in each case t o remove solvent and separate the products. The piperazine was isolated as colorless oprisms, all samples melting within a few degrees of 100 In each case the dibenzoyl derivative was prepared. The melting points of the dibenzoyl derivatives of each reaction product ranged from 193 t o 195". In all cases, a mixed melting point with an authentic sample of dibenzoylpiperazine showed no depression.
ments were repeated using ethylenediamine instead of diethylenetriamine. The formation of piperazine from ethylenediamine probably resulted through preliminary formation of diethylenetriamine which then condensed to form piperazine as described above.
