Synthesis and intramolecular recyclization of 2,2-dialkyl-6-chloro-4-hydroxymethyl-benzo[f]isoindolinium salts

The intramolecular cyclization of dialkyl(2-butynyl-4-hydroxy)[3-(p-chlorophenyl)propargyl]ammonium chlorides, catalyzed by aqueous KOH, was realized. It was shown that the obtained products — 2,2-dialkyl-6-chloro-4-hydroxymethylbenzo[f]isoindolinium chlorides — readily undergo recyclization under the action of a twofold molar amount of KOH in aqueous solution with heating with the formation of 4-dialkylaminomethyl-8-chloro-1,3-dihydronaphtho[1,2-c]furans.