Facile, novel and efficient synthesis of new pyrazolo[3,4-b]pyridine products from condensation of pyrazole-5-amine derivatives and activated carbonyl groups

Abstract

An efficient synthesis of novel ethyl-1,3,4-triphenyl-1H-pyrazolo[3,4-b]pyridine-6-carboxylate products has been achieved via condensation of pyrazole-5-amine derivatives and activated carbonyl groups, in refluxing acetic acid. This process has been found to be useful in the preparation of new N-fused heterocycle products in good to excellent yields.

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

“…Ketones engage in many organic reactions. The most important reactions follow from the susceptibility of the carbonyl carbon toward nucleophilic addition and the tendency for the enolates to add to electrophiles, most reactions of carbonyl compounds take place by one of four general mechanisms: nucleophilic addition (12)(13)(14)(15)(16)(17), nucleophilic acyl substitution, alpha substitution (18), and carbonyl condensation (6a-v) (Scheme 5).…”

“…[6][7][8][9][10][11][12][13][14] Due to their attractive pharmacological properties, pyrazolo [3,4-b]pyridines have attracted the attention of chemists who have researched ways to obtain the desired properties through different synthetic strategies. The most common reactions include: (a) condensation of pyrazole-5-amine derivatives and activated carbonyl groups; [15][16][17] (b) reaction of 5-aminopyrazoles, 1,3-dicarbonyl derivatives or equivalents and aldehydes through of Hantzsch-type reaction; [18][19][20] (c) through Povarov-type [4 + 2], cycloaddition between 5-aminopyrazoles, aromatic aldehydes, and cycloalkanones in acetic acid; 21 methylene ketones such as acetone or acetophenones with potassium hydroxide as basic catalyst. [22][23][24] The methods described in the literature presents several disadvantages such as the use of toxic solvents for the environment, long reaction times, several steps of synthesis, these contradict the current trends of green chemistry, 25 as a result of the importance that presents these heterocycles in the medicinal eld, different researchers have designed environmentally friendly and efficient synthetic routes, for example have used water as solvent under microwave irradiation (MWI) using catalysts organic or inorganic.…”

Iron oxide magnetic nanoparticles supported on amino propyl‐functionalized KCC‐1 as robust recyclable catalyst for one pot and green synthesis of tetrahydrodipyrazolopyridines and cytotoxicity evaluation

“…Several kinds of catalysts have been used to advance the reactions using MCRs (multicomponent reactions), such as acetic acid, carbonaceous material (C‐SO 3 H), p‐ TSA and L‐Proline . In recent years, the use of nanocatalysts has increased quickly and caused in the advancement of several active and capable nanocatalysts for various procedures .…”

KCC-1-NH2-DPA: an efficient heterogeneous recyclable nanocomposite for the catalytic synthesis of tetrahydrodipyrazolopyridines as a well-known organic scaffold in various bioactive derivatives

“…Several kinds of catalysts have been used to advance the reactions using MCRs, such as acetic acid [23], carbonaceous material (C-SO 3 H) [24], p-TSA [25] and L-proline [26]. In recent years, the use of nanocatalysts has increased quickly and caused in the advancement of several active and capable nanocatalyst for various procedures [27][28][29][30].…”