Convenient synthesis of fused heterocycles from α‐ketohydroximoyl chlorides and heterocyclic amines
1984; Wiley; Volume: 21; Issue: 4 Linguagem: Inglês
10.1002/jhet.5570210421
ISSN1943-5193
AutoresCyril Párkányi, Abdou O. Abdelhamid, John C. S. Cheng, Ahmad S. Shawali,
Tópico(s)Synthesis and Characterization of Heterocyclic Compounds
ResumoAbstract Nitroso derivatives of imidazo[1,2‐ a ]pyridine ( 11, 13, 14 ), imidazo[1,2‐ a ]pyrimidine ( 15 ), imidazo[1,2‐ a ]pyrazine ( 16 ), imidazo[1,2‐ b ]pyrazole ( 17 ), and imidazo[1,2‐ b ]‐1,2,4‐triazole ( 19 ) were obtained in good yields from α‐ketohydroximoyl chlorides 3 and 2‐aminopyridines ( 4–6 ), 2‐aminopyrimidine ( 7 ), 2‐aminopyrazine ( 8 ), 5‐amino‐3‐phenylpyrazole ( 9 ), and 3‐amino‐2 H ‐1,2,4‐triazole ( 10 ), respectively. Under different conditions, the reaction of 3 with 3‐amino‐2 H ‐1,2,4‐triazole ( 10 ) and 2‐aminopyrazine ( 8 ) afforded the noncyclized substitution products 18 and 22 , respectively. The structures of the products were assigned and confirmed on the basis of their elemental analyses, spectral data, and alternate synthesis wherever possible.
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