Published in:
Liebigs Annalen, 1996 (1996) 9, Seite 1477-1482
Language:
English
DOI:
10.1002/jlac.199619960921
ISSN:
0947-3440
Origination:
Footnote:
Description:
Ring‐Rearrangement During the Mitsunobu Alkylation of Phthalazinones and IndazololsThe Mitsunobu alkylation of substituted phthalazinones and indazolols with cyclic hydroxy‐ and hydroxymethyl‐substituted amines was investigated. In addition to the expected derivatives ring‐narrowed and ring‐enlarged rearrangement products were isolated and characterized by NMR spectroscopy. The occurence of these products can be explained by the existence of a bicyclic intermediate. The results of the reaction of phthalazinones with optically active amine compounds show a stereospecific reaction mechanism. The reaction of the phthalazinones leads to N‐substituted products, while in the case of the indazolols O‐substituted derivatives were isolated. A postulated bicyclic intermediate, 1‐methyl‐1‐azoniabicyclo[3.2.0]heptane, was synthesized as chloride.