REACTION OF BIS[1,3-DIPHENYL-2-IMIDAZOLIDINYLIDENE] WITH CARBONYL COMPOUNDS
HUANG Yao-Tseng; MA Jing-Ji; TAI Hsing-I Institute of Organic Chemistry, Academia Sinica
The reaction of bis(1,3-diphenyl-2-imidazolidinylidene) (I) with acetophenone gave two products, N,N'-diphenyl-N-(β-benzoylvinyl) ethylenediamine (III) and 1,3-diphenyl-2-phenacylimidazolidine (IV). Their yields depended on experimental conditions and IV could be converted to III on heating. Similarly, the reaction of I with cyclohexanone afforded N,N'-diphenyl-N-(α-oxo-cyclohexylidene-methyl)ethylenediamine (V) or 1,3-diphenyl-2-(α-oxo-cyclohexyl)imidazolidine (VI), depending on reaction conditions. 1,3-Diphenyl-2-benzoyl-imidazolidine (VIII) obtained from reaction of I with benzaldehyde could be reduced either by the Mccrwein-Ponndorf reaction or by treating with ethanthiol and anhydrous zinc chloride to 1,3-diphenyl-2-benzal-imidazolidine (IX). In the presence of air or iodine, IX produced a cationic radical which gave characteristic E S R signal.