4926-16-3Relevant academic research and scientific papers
Metal free [4+1] and [5+1] annulation reactions to prepare heterocycles using DMF and its derivatives as one-carbon source
Liu, Lingfeng,Qiao, Chunhua,Shen, Bei,Xu, Yiwen
, (2020/04/01)
1,2,4-Triazolo[3,4-a]pyridines and related heterocycles and substituted triazines were commonly discovered scaffolds in a variety of pharmaceutical and agrochemical agents. Herein, we report a highly efficient and practical method using DMF and its derivative for the [4+1] and [5+1] annulation reactions to prepare these heterocycles. This metal free reaction takes advantages of shelf stable DMF as solvent and carbon donor, imidazole chloride as a catalyst, the mild reaction condition tolerates a broad substrate range and substitutes. The prepared 3-unsubstituted 1,2,4-triazolo[3,4-a]pyridine and derivatives allow further introduction of a variety of functional group1 at 3-position.
One-pot synthesis of N-fused 1,2,4-triazoles and related heterocycles via I2/TBHP-mediated oxidative C–N bond formation
Wu, Yachuang,Yang, Yifeng,Qi, Yinliang,Du, Shimei,Zhang, Yongsheng,Ding, Liang,Zhao, Yanfang
supporting information, p. 4216 - 4220 (2018/10/26)
A metal-free iodine/TBHP-mediated oxidative C–N bond formation for the one-pot synthesis of N-fused 1,2,4-triazoles and related heterocycles via cyclization has been developed. This reaction which is amenable to scale-up affords the corresponding products with good to excellent yields and tolerates a wide range of functional groups.
A mild synthesis of [1,2,4]triazolo[4,3-a]pyridines
Schmidt, Michael A.,Qian, Xinhua
supporting information, p. 5721 - 5726 (2013/09/24)
The reaction between 2-hydrazinopyridines and ethyl imidates was examined as a one-pot method for rapidly preparing [1,2,4]triazolo[4,3-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]triazolo[1,5-a]pyridines.
The Preparation of 3-Phenyltriazolopyridines and Their Benzologs from N-(Phenylsulfonyl)benzohydrazonoyl Chloride and Pyridines
Ito, Suketaka,Kakehi, Akikazu,Matsuno, Toshiyuki,Yoshida, Jun-ichi
, p. 2007 - 2011 (2007/10/02)
3-Phenyltriazolopyridines were obtained in good yields from N'-benzenesulfonohydrazidates, generated from 2-unsubstituted pyridines and N-(phenylsulfonyl)benzohydrazonoyl chloride (2), by oxidation with chloranil.The reaction of quinoline and isoquinoline with 2 gave 1-phenyl-3-phenylsulfonyl-3,3a-dihydrotriazoloquinoline and 3-phenyl-1-phenylsulfonyl-1,10b-dihydrotriazoloisoquinoline respectively, both in good yields; they aromatized to the corresponding triazoles by the 1,2-elimination of benzenesulfinic acid on heating.
