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The molecular structure and chemical reactivities of the condensation products of o ‐substituted benzylidenacetylacetone with hydrazine dihydrochloride
Author(s) -
Kurihara Takushi,
Sugiyama Mariko,
Hirano Hiroshi,
Tomita KenIchi,
Sakaki Masayoshi
Publication year - 1975
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.5570120321
Subject(s) - chemistry , hydrazine (antidepressant) , acetonitrile , methanol , condensation , hydrochloride , halogenation , condensation reaction , pyrolysis , medicinal chemistry , organic chemistry , hydrate , catalysis , chromatography , physics , thermodynamics
Reaction of o ‐nitrobenzylideneacetylacetone ( 1a ) with hydrazine dihydrochloride in methanol gave 4‐(α‐methoxy‐ o ‐nitrobenzyl)‐3,5‐dimethylpyrazole hydrochloride ( 4a ), whose structure was unambigously confirmed by an X‐ray crystallographic analysis, via 4‐( o ‐nitrobenzylidene)‐3,5‐dimethylisopyrazole ( 2a ). Compound 2a was synthesized by condensation of 1a with hydrazine dihydrochloride in acetonitrile. Analogously the corresponding o ‐chloro derivatives ( 2b, 4b ) were obtained. These were converted to N ‐methyl ( 6b ) and N ‐acetyl ( 7a,b ) derivatives and the behaviors on bromination and pyrolysis were investigated.