Accession Number : AD0710709

Title :   INTERACTION OF HETEROCYCLES AND NUCLEOPHILES. II. SIGMA COMPLEXES FORMED FROM METHOXIDE ION AND METHOXY-3,5-DINITROPYRIDINES IN DIMETHYL SULPHOXIDE,

Corporate Author : DEFENCE STANDARDS LABS MARIBYRNONG (AUSTRALIA)

Personal Author(s) : Biffin,M. E. C. ; Miller,J. ; Moritz,A. G. ; Paul,D. B.

Report Date : 19 JAN 1970

Pagination or Media Count : 6

Abstract : Contrasting behaviour is observed when 2- and 4-methoxy-3,5-dinitropyridine interact with methoxide ion in dimethyl sulphoxide. The 4-methoxy compound affords both methine and acetal sigma complexes, the latter being thermodynamically more stable. The interconversion is catalysed by methanol. Labelling experiments have established that the sigma complex from the 2-methoxypyridine is formed by addition at C6; no conversion into the acetal could be effected. These observations are rationalized in terms of differential steric and solvation effects. Demethylation and rearrangement reactions of 4-methoxy-3,5-dinitropyridine are reported. (Author)

Descriptors :   (*PYRIDINES, *IONS), MOLECULAR ISOMERISM, COMPLEX COMPOUNDS, NUCLEAR MAGNETIC RESONANCE, ORGANIC SOLVENTS, AUSTRALIA

Subject Categories : Organic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE