New findings in the richter reaction in series of vicinal alkynylpyrazolyldiazonium salts

Eugene V. Tretyakov, Sergei F. Vasilevsky

Результат исследований: Материалы для журналаСтатьярецензирование

5 Цитирования (Scopus)

Аннотация

When treated with sodium nitrite in hydrochloric or hydrobromic acid, positional isomers of vic-alkynylaminopyrazoles were transformed to the pyrazolopyridazines via cyclization of the corresponding alkynylpyrazolyldiazonium salt. The reaction was found to depend on the position of alkynyl and diazonium group in pyrazole nuclei: the heterocyclization of 5-alkynylpyrazolyl-4-diazonium salts underwent at 100-105 °C and gave 7-chloro-1H-pyrazolo[4,3-c]p;yridazines; the heterocyclization of 4-alkynylpyrazolyl-3-diazonium salts at 50-60 °C gave 6-hydroxy-2H-pyrazolo[3,4-c]pyridazines as major component and 6-halogeno-2H-pyrazolo[3,4-c]pyridazines as minor component; the cyclization of 3-alkynylpyrazolyl-4-diazonium salts accompanying with methyl group migration towards the neighbouring nitrogen atom afforded 7-chloro-1H-pyrazolo[4,3-c]pyridazines.

Язык оригиналаАнглийский
Страницы (с-по)519-524
Число страниц6
ЖурналHeterocyclic Communications
Том4
Номер выпуска6
DOI
СостояниеОпубликовано - 1 янв 1998
Опубликовано для внешнего пользованияДа

ASJC Scopus subject areas

  • Organic Chemistry

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