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Synthesis of some derivatives of imidazo[1,2‐ a ]pyridine, pyrazolo[1,5‐ b ]imidazole, and 4‐(3 H )quinazolinone from α‐ketohydrazidoyl bromides
Author(s) -
Shawali Ahmad S.,
Sami M.,
Sherif S. Mourad,
Párkányi Cyril
Publication year - 1980
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.5570170507
Subject(s) - chemistry , triethylamine , yield (engineering) , imidazole , pyridine , quinazolinone , ethanol , medicinal chemistry , aryl , proton nmr , organic chemistry , alkyl , materials science , metallurgy
α‐Aroyl‐ N ‐arylhydrazidoyl bromides 1 react with 2‐aminopyridine in ethanol and give 2‐aryl‐3‐arylazo‐imidazo[1,2‐α]pyridines 2 in 60‐75% yield. The reaction of 1 with 3‐phenyl‐5‐aminopyrazole in ethanol leads to 2,6‐diaryl‐3‐arylazo‐1 H ‐pyrazolo[1,5‐ b ]imidazoles 3 in almost quantitative yield. Also, 1 react with anthran‐ilic acid in the presence of triethylamine giving 3‐arylamino‐2‐aroyl‐4‐(3 H )quinazolinones 4 in 80‐85% yield. The structures of the products were assigned and confirmed on the basis of their elemental analysis and electronic absorption, infrared and nmr spectra.