Heterocyclische Spirocyclohexadienone aus substituierten Phenolen / Heterocyclic Spirocyclohexadienones from Substituted Phenols

Abstract

Mannich bases were prepared from substituted phenols with aliphatic amines and formaldehyde. Amine exchange with N-methyl-2-naphthylamine followed by a Hofmann Martius rearrangement gave rise to o,o′-amino-hydroxy-diphenylmethane derivatives. Under cyclization conditions some of these compounds produced spirocyclohexadienones, which are the ipso analogs to the hypothetic intermediates postulated in the aminomethylation mechanism of phenols.