CONVENIENT SYNTHESIS OF IMIDAZO[1,5-<i>a</i>]PYRIMIDINE DERIVATIVES AND THEIR UNUSUAL RECYCLIZATION INTO 3<i>H</i>-IMIDAZO[4,5-<i>b</i>]PYRIDINE DERIVATIVES
DOI:
https://doi.org/10.1007/5988Ключевые слова:
1, 3-diketones, 1H-imidazol-4(5)-amine, imidazo[4, 5-b]pyridines, imidazo[1, 5-a]pyrimidines, trifluoroacetic acid, carbonylation, Dimroth rearrangement.Аннотация
New derivatives of imidazo[1,5-a]pyrimidine have been synthesized by cyclization of in situ generated 1H-imidazol-4(5)-amine with 1,3-diketones or malondialdehyde derivatives. Utilization of asymmetrical 1,3-diketones leads to the formation of a mixture of regioisomers. The discovered conversion of imidazo[1,5-a]pyrimidine core into 3H-imidazo[4,5-b]pyridine that takes place only under acidic conditions can be considered as a new version of Dimroth rearrangement involving cleavage of C–N bond and formation of C–C bond.Загрузки
Опубликован
2021-05-26
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Раздел
Оригинальные статьи