Abstract
The alkylation of 4-oxo-3,6,6-trimethyl-4,5,6,7-tetrahydroindazole with alkyl halides forms mixtures of 1-alkyl and 2-alkyl derivatives which have been separated by fractional crystallization from n-hexane. The 4-oxo-1-alkyl-,-1-aryl-, and -1-acyl-4,5,6,7-tetrahydroindazoles have characteristic frequencies in their IR spectra at 1540-1530 cm−1, and the corresponding 2-substituted derivatives have frequencies at 1565-1555 cm−1. The introduction of an alkyl substituent at a nitrogen atom decreases the basicity of 4,5,6,7-tetrahydroindazole by 0.6 orders of magnitude, the 1-alkyl isomers being somewhat stronger bases than the 2-alkyl isomers.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
I. Strakova, A. Strakov, M. Strautzele, and E. Gudrinietse, Izv. AN LatvSSSR, ser. khim., 597, 1968.
I. Strakova, Ya. Linaberg, and E. Gudrinietse, Izv. AN LatvSSR, ser. khlm., 718, 1968.
R. Mecke and K. Hoack, Ber., 93, 210, 1960.
M. Ochiai and J. Kamikado, Chem. Pharm. Bull., 12, 1515, 1964.
French Patent no. 1369476, 1964, C. A., 61, 16073, 1964.
I. Grandberg, ZhOKh, 33, 519, 1963.
M. Clinton and A. Manson, J. Am. Chem. Soc. 83, 1478, 1961.
I. Grandberg and A. Kost, ZhOKh, 32, 1556, 1962.
T. Jacobs, in: Heterocyclic Compounds, [Russian translation], IL, 5, 43, 1960.
K. Auwers and A. Niemeyer, J. pr. Chem., 110, 153, 1925.
M. Paul and F. Long, Chem. Rev., 57, 1, 1957.
E. A. Mistrykov, Coll., 26, 207, 1961.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Strakova, I.A., Gudrinietse, E.Y., Linaberg, Y.Y. et al. Alkylation of 4-oxo-3-methyl-4,5,6,7-tetrahydroindazoles. Chem Heterocycl Compd 6, 481–485 (1970). https://doi.org/10.1007/BF00478397
Issue Date:
DOI: https://doi.org/10.1007/BF00478397