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A new class of heterocyclic betaines: 1,1‐dimethyl‐3‐phenylpyrazolium‐5‐oxide
Author(s) -
HeneryLogan Kenneth R.,
Keiter Ellen A.
Publication year - 1970
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570070428
Subject(s) - chemistry , tautomer , methanol , organic chemistry , oxide , medicinal chemistry
1,1‐Dimethyl‐3‐phenylpyrazolium‐5‐oxide (1) was isolated as a minor product (3%) in the reaction of ethyl benzoylacetate with 1,1‐dimethylhydrazine and also was obtained as the major product (58%) from the reaction of methyl p ‐toluenesulfonate with ethyl benzoylacetate dimethylhydrazone. The structural assignment was made on the basis of chemical reactions and spectral data and the formula is represented by a resonance structure for which there are two principal canonical forms. Reaction of 1 with methanol at room temperature afforded methyl benzoylacetate dimethylhydrazone. Ethyl benzoylacetate dimethylhydrazone was shown to exist as a tautomeric mixture containing 65% of the imine form at room temperature.