Design, synthesis and biological activity of acyl substituted 3-amino-5-methyl-1,4,5,7-tetrahydropyrazolo[3,4-b]pyridin-6-ones as potential hypnotic drugs

Qsar Studies, and in Silico Adme Prediction of P-Aminosalicylic Acid Derivatives as Neuraminidase Inhibitors

“…All the molecular modeling and statistical analysis were performed using Vlife MDS software [18][19][20] . The structures of the compounds were built using molecular sketching facilities provided in the modeling environment of Virus life.…”

Synthesis of Pyrazolo[3,4‐b]pyridin‐6‐ones

“…The classical method of synthesizing 3‐aminopyrazoles is the reaction of closing the pyrazole ring during reaction of hydrazine and o ‐amino cyano derivatives [7–9]. The same approach was used in several studies [10–13] in the synthesis of 6‐oxopyrazolo[3,4‐ b ]pyridines with the intermediate formation of derivatives of 3‐cyano‐6‐oxopyridine.…”

“…A recent study [12] showed that the reaction of methyl methacrylate ( 10 ) and malononitrile in the presence of sodium methoxide in boiling methanol resulted in 1,4,5,6‐tetrahydropyridine‐3‐carbonitrile ( 11 ) in a 50% yield. In this case, the reactants for the synthesis of pyrazolopyridines were not aromatic derivatives; they were cyclic alkoxy enaminonitriles of the type ( 11 ; the aforementioned dearomatization did not occur).…”

“…Also, carbamides ( 15 ) were synthesized in the reaction of pyridine ( 14 ) with isocyanates R 2 NCO, in a 49–87% yield. The authors of the article [12] note that when pyrazolo[3,4‐ b ]pyridine ( 12 ) reacts with furan‐2‐carbonyl or thiophene‐2‐carbonyl chlorides, the reaction takes place selectively with the nitrogen of the pyrazole ring and does not affect the free amino group. The compounds thus obtained ( 16 ) were introduced into the reaction with isocyanates R 2 NCO in the pyridine medium with the formation of carbamide derivatives ( 17 ; Scheme 4).…”

An Unequivocal Synthesis of 2‐Aryl Substituted 3‐Amino‐2,4,5,7‐tetrahydro‐6H‐pyrazolo[3,4‐b]pyridin‐6‐ones

“…As a part of our ongoing research in the area of tyrosine kinase inhibitors, we were interested in 3‐amino‐2,4,5,7‐tetrahydro‐6 H ‐pyrazolo[3,4‐ b ]pyridin‐6‐ones as an scaffold for the synthesis of combinatorial libraries. Such structures can be obtained by cyclization of 2‐methoxy‐6‐oxo‐1,4,5,6‐tetrahydropyridin‐3‐carbonitriles ( 1 ), synthesized by reaction of an α,β‐unsaturated ester and malononitrile in NaOMe/MeOH, with hydrazine or substituted hydrazines. In this later case, the reaction can lead to two different positional isomers ( 2 or 3 ) depending on the reaction path.…”