Synthesis of 1H-pyrazolo[3,4-b]pyridine 5-ketones was written by Denzel, Theodor;Hoehn, Hans. And the article was included in Archiv der Pharmazie (Weinheim, Germany) in 1976.Recommanded Product: 3528-58-3 This article mentions the following:
Pyrazolopyridine ketones I [R1 = Me, R5C6H4 (R5 = H, 3-, 4-Cl, 4-Me, 4-MeO), R2 = H, Me, R3 = Et, furfuryl, Me2CH, CH2Ph, H, R4 = H; R1 = Ph, R2 = H, R3 = furfuryl, R4 = Me] were prepared and converted to analogs. EtO2CCH2COR1 reacted with R2C(OEt)3 to give 45-73% β-oxo esters EtO2CC(COR1):CR2OEt which condensed with 5-aminopyrazoles in a modified Gould-Jacobs reaction to give 55-95% enamines II. These cyclized at 250-300° to give 45-79% I. I were alkylated to give III (R6 = Et, CH2CH2CHMe2) or chlorinated to the 4-Cl analogs, which reacted with amines to give IV (R7 = CHMeEt, 2-pyrimidinyl, Bu, H, Ph). Since the preparation of necessary EtO2CCH2COR1 was sometimes difficult, III (R1 = Et, Bu, decyl, R2 = R4 = H, R3 = R6 = Et) were prepared from the corresponding III (R1 = Cl) and R1MgX-CdCl2. In the experiment, the researchers used many compounds, for example, 1-Ethyl-1H-pyrazol-5-amine (cas: 3528-58-3Recommanded Product: 3528-58-3).
1-Ethyl-1H-pyrazol-5-amine (cas: 3528-58-3) belongs to pyrazole derivatives. The strategies for the synthesis of pyrazoles generally can be applied for the construction of indazoles. Pyrazole rings have been used as core components of several leading non-steroidal anti-inflammatory drugs (NSAIDs) and antihypertensive drugs. It has also been found to be useful as a bifunctional ligand for metal catalysis.Recommanded Product: 3528-58-3
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics