Search for a nonelectrocyclic cyclization of nitrosostyrene: Rearrangements of Michael adducts from DMAD and alpha-dialkylamino oximes

Coskun N., Arikan N.

TURKISH JOURNAL OF CHEMISTRY, vol.27, no.1, pp.15-20, 2003 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 27 Issue: 1
  • Publication Date: 2003
  • Journal Name: TURKISH JOURNAL OF CHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, TR DİZİN (ULAKBİM)
  • Page Numbers: pp.15-20
  • Bursa Uludag University Affiliated: Yes

Abstract

The aza-Claisen rearrangement product of the Michael adducts 2 from alpha-dialkylaminoacetophenone oximes and DMAD underwent fragmentation to give dialkylaminomaleate, and benzonitrile at reflux in acetonitrile. The fragmentation was assumed to proceed through an unstable 4H-1,2-oxazete 6. The same reaction performed at room temperature, in addition to the nitrile and maleate, gave the corresponding 2-(2-dialkylamino-1-phenylethylideneaminooxy)-but-2-enedioic acid dimethyl esters 8 and 9. Compounds 9 isomerized to 8 on heating in acetonitrile.