Synthesis of N-aminopyrazoles by Fe(II)-catalyzed rearrangement of 4-hydrazonomethyl-substituted isoxazoles

Ekaterina E. Galenko, Viktor K. Ivanov, Mikhail S. Novikov, Andrey A. Zolotarev, Alexander F. Khlebnikov

Результат исследований: Научные публикации в периодических изданияхстатья

3 Цитирования (Scopus)

Аннотация

A novel effective method is reported for the preparation of 1-amino-1H-pyrazole-4-carboxylic acid derivatives by Fe(II)-catalyzed rearrangement of isoxazoles having (2,4-dinitrophenylhydrazono)methyl substituent at C4. The reaction proceeds smoothly for both E and Z isomers of 4-(hydrazonomethyl)isoxazoles, and this means it is not necessary to separate mixtures of E/Z-isomers of the hydrazones prepared by reaction of 5-methoxy/pirrolidino-4-carbonylisoxazoles and 2,4-dinitrophenylhydrazine. The rearrangement proceeds via the formation of an aziridine intermediate which can be isolated in certain cases. The 2-nitro group in the synthesized 1-[(2,4-dinitrophenyl)amino]-1H-pyrazole-4-carboxylic esters can be selectively reduced in two steps via acylation of the amino group followed by hydrogenation-deacylation using H2-Pd/C.

Язык оригиналаанглийский
Страницы (с-по) 6288-6298
Число страниц11
ЖурналTetrahedron
Том74
Номер выпуска43
DOI
СостояниеОпубликовано - 25 окт 2018

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Предметные области Scopus

  • Биохимия
  • Поиск новых лекарств
  • Органическая химия

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