AROMATIC REPLACEMENT WITH REARRANGEMENT .2. CHLORODEACYLATION IN CHLORINATION OF ACETOXYNAPHTHALENES

The trichloro-product (m.p. 174°), obtained by chlorination of 1,5-diacetoxynaphthalene in acetic acid or in carbon disulphide, has been shown to be 5-acetoxy-2,4,4-trichloro-(4H)-naphthalen-1-one. Chlorination in chloroform as solvent, however, has now been shown to give 5-acetoxy-2,3,4- trichloro-3,4-dihydro-(2H)-napthalen-1-one as a major product, which can be dehydrochlorinated to give 5-acetoxy-2,4-dichloro-1-naphthol. This on chlorination in chloroform gives 5-acetoxy-2,2,4-trichloro-(2H)-naphthalen-1- one. These results are discussed with reference to other deacylations accompanying aromatic substitution in aryl esters, and to the halogenation of enol-esters.