Microwave-assisted one-pot synthesis in water of carbonylpyrazolo[3,4-b]pyridine derivatives catalyzed by InCl₃ and sonochemical assisted condensation with aldehydes to obtain new chalcone derivatives containing the pyrazolopyridinic moiety

Abstract

Pyrazolo[3,4-b]pyridines derivatives have been synthesized via one-pot condensation of 3-methyl-1-phenyl-1H-pyrazolo-5-amine (1), paraformaldehyde (2) and β-diketones (3) under microwave irradiation in aqueous media catalyzed by InCl3.

Recent Advances of Indium(III) Chloride Catalyzed Reactions in Organic Synthesis

“…In 2017, Gutiérrez group employed indium trichloride in water under microwave irradiation [39] for the construction of Pyrazolo[3,4‐b]pyridine derivatives 15 a – i via one‐pot three components tandem reaction of 3‐methyl‐1‐phenyl‐1H‐pyrazolo‐5‐amine 12 , formaldehyde 13 and β‐diketones 14 (Scheme 4).…”

Synthesis of heterocyclic compounds via Michael and Hantzsch reactions

“…Compounds 102 were also prepared by the reaction of the same reactants in the presence of diammonium hydrogen phosphate as a catalyst under conventional heating condition in good yields 85% to 95% (Scheme 55). [135] [137] reported the synthesis of pyrazolo [3,4-b] quinolin-5(6H)-one 107 by the reaction of formaldehyde with 3-methyl-1-phenyl-1H-pyrazolo-5-amine 106 and cyclohexane-1,3-diones 72 and 72a under microwave irradiation in aqueous media catalyzed by InCl 3 (Scheme 57).…”

3-(3,4-Dimethoxyphenyl)-5-(2-fluorophenyl)-1-phenyl-4,5-dihydro-1H-pyrazole

“…Molbank 2019, 2019, x 2 of 6 substituted pyrazole, formaldehyde, and β-diketone under 300 W microwave irradiation [18]. However, the use of a microwave reactor in one-pot synthesis of pyrazoline from substituted benzaldehyde, acetophenone, and phenylhydrazine has not been reported previously.…”

“…Other researchers have also reported one-pot synthesis of pyrazolines from various starting materials and methods such as from 3-butynol and substituted phenylhydrazine under reflux condition [12], from substituted acetophenone, benzaldehyde, and phenylhydrazine under reflux condition [13,14] and through the formal [4 + 1] annulation reaction of 3-bromooxindoles and in situ-derived 1,2-diaza-1,3-dienes by stirring at room temperature [15]. In addition, it has also been reported that the one-pot synthesis of pyrazolines can be performed by reacting pyridine based chalcone and hydrazine hydrate under 300 W microwave irradiation [16]; by reacting substituted chalcone, hydrazine hydrate, and acetic anhydride under 550 W microwave irradiation [17]; and by reacting substituted pyrazole, formaldehyde, and β-diketone under 300 W microwave irradiation [18]. However, the use of a sealed-vessel reactor in one-pot synthesis of pyrazoline from substituted benzaldehyde, acetophenone, and phenylhydrazine has not been reported previously.…”