Metal and acid-free synthesis of acenaphthenone-2-ylidene ketones in PEG 400 and their radical nitration by TBN in water

Abstract

The synthesis of acenaphthenone-2-ylidene ketones has been developed using PEG 400 as a solvent under metal and acid-free conditions. Using TBN as a nitrating agent under atmospheric oxygen, nitration of acenaphthenone-2-ylidene ketones has been accomplished for the first time. Upon nitration, (E)-2-(2-oxo-2-phenylethylidene)acenaphthylen-1(2H)-one and alkyl (E)-2-(2-oxoacenaphthylen-1(2H)-ylidene)acetate give the diastereomer with the same geometry. The variety of substrates employed and low cost and non-toxicity of the chemicals used in this process demonstrate its important applicability. Another noteworthy aspect of the procedure is that, in contrast to previous procedures, it does not use HNO₃ or metal nitrates during the transformation.