Use of the α-amination reaction for the synthesis of pyrazole derivatives containing carbo- and heterocyclic substituents on the nitrogen atom
- 246 Downloads
A method has been developed for the synthesis of pyrazoles with carbo- and heterocyclic substituents on the nitrogen atom based on the α-amination reaction of carbo- and heterocyclic ketones, using azodicarboxylate–L-proline system with subsequent interaction with malonodialdehyde tetramethyl-acetal. In the case of carbocyclic ketones and tetrahydro-γ-pyranone, the reaction occurs stereo-selectively to give chiral hydrazines and pyrazoles. With derivatives of piperidin-4-one, α-amination is accompanied by racemization.
Keywordsazodicarboxylate cyclohexanone cyclopentanone N-substituted piperidones pyrazoles L-proline tetrahydro-γ-pyranone stereoselective α-amination
- 2.Y. L. Bennani, M. G. Campbell, D. Dastrup, and E. P. Huck, US Pat. Appl. 20070197526.Google Scholar
- 3.A. V. Kurkin, A. A. Utkina, and M. A. Yurovskaya, Khim. Geterotsikl. Soed., 127 (2008). [Chem. Heterocycl. Compd., 44, 106 (2008)].Google Scholar
- 7.R. S. Alekseev, A. V. Kurkin, and M. A. Yurovskaya, Khim. Heterotsikl. Soed., 706 (2011).[Chem. Heterocycl. Compd., 47, 584 (2011)].Google Scholar