Water → N-Cyclohexyl-1,2-ethanediamine

Participants

Reaction Steps

To a 850 cc glass liner for a rotating autoclave was charged 12.25 g (0.125 mole) cyclohexanone, 3.7 g of a catalyst consisting of 0.3 weight percent platinum (sulfided) on alpha alumina, and an 80 weight percent solution of ethylenediamine in de-ionized water (37.5 g (0.63 mole) ethylenediamine and 9.37 g (0.52 mole) water). An exotherm was generated immediately associated with the formation of Schiff bases from the reaction of cyclohexanone and ethylenediamine. The liner was placed into a rotating autoclave, purged with nitrogen, charged to 1,000 psig with hydrogen or 500 psig each of hydrogen and nitrogen, and then the autoclave was rotated at approximately 30 rpm for 6-8 hours at 160°-180° C. The cooled liner was vented, flushed with nitrogen to avoid catalyst ignition, and the cooled product mixture was removed to afford a clear to pale yellow viscous liquid containing some solids which were principally N,N'-dicylohexyl ethylenediamine (DICEDA). The product mixture was filtered through diatomaceous earth to remove catalyst and DICEDA, and the resulting filtrate contained, in addition to unreacted ethylenediamine, CEDA with only traces of DICEDA. The liner and filter cake were rinsed with methanol and subsequent removal of volatile material at 80° C. afforded product which was principally DICEDA. Removal of volatiles at 80° C. at 30 inches vacuum afforded 15 grams CEDA. Conversion of cyclohexanone amounted to 99+% with a 95% yield of CEDA and 5% DICEDA.

Provenance & Evidence