Reactions of unsaturated acid halides. Part II. Aluminium chloride-catalysed reactions of phenylpropioloyl chloride with anisole, toluene, and naphthalene

Abstract

A new product of the Friedel–Crafts acylation of anisole with phenylpropioloyl chloride has been identified as mixed crystals of β-chloro-4′-methoxychalcone and p-methoxyphenyl phenylethynyl ketone, the main and previously obtained product. In the analogous reaction of the acid chloride with toluene, the principal product was β-(p-tolyl)-4′-methylchalcone, but some phenylethynyl p-tolyl ketone was also isolated. Although the aluminium chloride-catalysed decomposition of the acid chloride in naphthalene gave mainly 1-naphthyl phenylethynyl ketone, some 3-phenylphenalen-1-one was also formed. The preparation of the aforementioned acetylenic ketones and 2-naphthyl phenylethynyl ketone from the corresponding styryl compounds is described, and the relative importance of the various processes encountered in the aluminium chloride-catalysed reactions discussed in outline.