A mild synthesis of [1,2,4]triazolo[4,3-a]pyridines |
| |
Authors: | Michael A Schmidt Xinhua Qian |
| |
Institution: | Chemical Development, Bristol-Myers Squibb, 1 Squibb Drive, New Brunswick, NJ 08903, United States |
| |
Abstract: | The reaction between 2-hydrazinopyridines and ethyl imidates was examined as a one-pot method for rapidly preparing 1,2,4]triazolo4,3-a]pyridines. A diverse set of 2-hydrazinopyridines were cyclized with a variety of alkyl- and aryl-substituted ethyl imidates in good yields. The reaction proceeds optimally under mild conditions (50−70 °C) using 1.5 equiv of acetic acid. The electronic and steric properties of the hydrazine and imidate strongly impact the rate of the reaction. When highly electron deficient 2-hydrazinopyridines were used, the products rearranged to 1,2,4]triazolo1,5-a]pyridines. |
| |
Keywords: | Triazolopyridine Heterocycle Imidate Hydrazinopyridine Acid promoted |
本文献已被 ScienceDirect 等数据库收录! |
|