914-95-4Relevant academic research and scientific papers
A mild method for the synthesis of bis-pyrazolo[3,4-b:4′,3′-e]pyridine derivatives
Qiu, Rui,Qiao, Shujia,Peng, Boyu,Long, Jiajia,Yin, Guodong
supporting information, p. 3884 - 3888 (2018/09/27)
A mild and efficient method for the synthesis of bispyrazolo[3,4-b:4′,3′-e]pyridines from 5-aminopyrazoles and aromatic aldehydes using an inexpensive FeCl3 catalyst is reported. The reaction temperature was reduced from 220–250 °C to 130 °C compared to conventional methods. A large proportion of the products precipitated directly from the mixture at room temperature. Aliphatic and α,β-unsaturated aldehydes selectively resulted in formation of the corresponding 1H-pyrazolo[3,4-b]pyridine derivatives. A possible domino reaction mechanism was also proposed. Several aryl alkynyl groups were introduced to these tricyclic molecules via the Sonogashira coupling reaction.
A green and efficient synthesis of furo[3,4-e]pyrazolo[3,4-b]-pyridine derivatives in water under microwave irradiation without catalyst
Shi, Feng,Wang, Qian,Tu, Shujiang,Zhou, Jianfeng,Jiang, Bo,Li, Chunmei,Zhou, Dianxiang,Shao, Qingqing,Cao, Longji
, p. 1103 - 1108 (2008/12/20)
(Chemical Equation Presented) A series of furo[3,4-e]pyrazolo[3,4-b] pyridine analogues of podophylloxin were synthesized via three-component reactions of aldehydes, 3-methyl-1-phenyl-1H-pyrazol-5-amine and tetronic acid in water under microwave irradiation without catalyst. This efficient synthesis not only offers an economical and green synthetic strategy to this class of significant compounds but also enriches the investigations on microwave-assisted synthesis in water.
Ionic liquid as an efficient promoting medium for synthesis of bis-pyrazolo[3,4-b:4′,3′-e]pyridines
Shi, Da-Qing,Yang, Fang
experimental part, p. 755 - 760 (2009/12/03)
The preparation of a series of bis-pyrazolo[3,4-b:4′,3′-e] pyridines by the reaction of 5-aminopyrazole with aldehydes in ionic liquid [bminiJBr is described. This new method has the advantages of easier work-up, milder reaction conditions, high yields and environmental friendliness compared with other methods.
Solvent-free microwave synthesis of bis-pyrazolo[3,4-b:4′,3′-e] pyridines and study of their antifungal properties
Quiroga,Portilla,Insuasty,Abonia,Nogueras,Sortino,Zacchino
, p. 61 - 66 (2007/10/03)
The synthesis of a series of bis-pyrazolo[3,4-b:4′,3′-e] pyridines (3) in the reaction of 5-amino-3-methyl-1-phenylpyrazole (1) with aldehydes (2) under microwave irradiation and solvent-free conditions is described. The structure elucidation of the produ
Synthesis of Benzylidenaminopyrazoles and Bispyrazolopyridines
Hennig, L.,Hofmann, J.,Alva-Astudillo, M.,Mann, G.
, p. 351 - 358 (2007/10/02)
5-Aminopyrazoles 1a-e react with aromatic aldehydes in boiling ethanol to yield azomethines 2a-n.Bispyrazolopyridines 7a-f are obtained by the reaction of 2a-f with an excess of aminopyrazole at higher temperatures via bisaminopyrazoles 5 and bispyrazolodihydropyridines 6.Structure and configuration of the products are assigned by n.m.r. spectroscopy.Reactions with replacement of the arylidene group on azomethine 2b suggest that the transformation of azomethines to bisaminopyrazoles occurs through a mechanism involving addition of the CH-acidic component, with subsequent elimination of aminopyrazole.
