ISSN:
1573-8353
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The peculiarities of the Fischer cyclization of cyclohexanone 4-pyridylhydrazone and the formation of 5,6,7,8-tetrahydro-γ-carboline, 4-aminopyridine, 4-ethylaminopyridine, 4-pyridone, and 2-(4-pyridyl)-3,3a,4,5,6,7-hexahydroindazole-3-spirocyclohexane under the conditions of this reaction are examined. In the case of I, as also for the isomeric 2-pyridylhydrazones, catalysts can be arranged in the following order with respect to their ability to increase the yield of the normal indolyzation product: cuprous chloride ≈ sulfosalicyclic acid 〈 polyphosphoric acid 〈 p-toluenesulfonic acid 〈 zinc chloride. It was established that the indolyzation of I proceeds also without acid catalysts under the influence of sodium ethoxide.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00477424
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