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Studies on enaminonitriles: A new synthesis of 1,3‐substituted pyrazole‐4‐carbonitrile
Author(s) -
Ghozlan Said Ahmed Soliman,
Abdelhamid Ismail Abdelshafy,
Elnagdi Mohamed Hilmy,
Gaber Hatem Moustafa
Publication year - 2005
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.5570420623
Subject(s) - chemistry , pyrazole , hydrazine (antidepressant) , yield (engineering) , medicinal chemistry , hydrate , dimethylformamide , hydrazone , malononitrile , pyridine , chlorobenzene , organic chemistry , materials science , chromatography , solvent , metallurgy , catalysis
3‐Diethylaminoacrylonitrile ( 1 ) reacts with hydrazonyl halides ( 2a‐d ) to yield 1,3‐disubstituted pyrazole‐4‐carbonitriles 5a‐d. The acetyl 1‐ p ‐chlorophenylpyrazole‐4‐carbonitrile ( 5a ) condensed with hydrazine hydrate to yield the bishydrazone 10 and with dimethylformamide dimethylacetal to yield 1‐aryl‐3‐(3‐dimethylamino)acryloyl pyrazole‐4‐carbonitrile ( 11 ). This enamine reacts with hydrazine hydrate to yield the pyrazolylpyrazole ( 12 ) and with naphthoquinone to yield the 3‐naphthofuranoyl pyrazole 13. The pyra‐zolyl pyridine derivative 14 was obtained upon treatment of 11 with acetylacetone in the presence of ammonium acetate. Compound 11 was coupled with p ‐chlorobenzene diazonium chloride to yield the hydrazone 16 that was coupled further with p ‐chlorobenzenediazonium chloride to yield the formazane 18.