Facile Synthesis of New 6‐Alkylamino‐1H‐pyrazolo[3,4‐b]pyridine‐5‐carbonitrile Derivatives

Abstract

in Wiley Online Library (wileyonlinelibrary.com).Some new derivatives of 6-alkylamino-1,3-diphenyl-1H-pyrazolo[3,4-b]pyridine-5-carbonitrile have been prepared through a Knoevenagel condensation reaction of 5-chloro-1,3-diphenyl-1H-pyrazole-4-carbaldehyde with malononitrile in ethanol containing a few drops of glacial acetic acid at reflux temperature followed by cyclization with primary alkyl amines in the presence of 1,8-diazabicyclo[5.4.0] undec-7-ene as catalyst in refluxing ethanol. The products were characterized on the basis of IR, 1 H NMR, and 13 C NMR spectral and microanalytical data. The 1 H NMR data ruled out the formation of the alternative cyclized isomers 6-imino-7-alkyl-1,3-diphenyl-6,7-dihydro-1H-pyrazolo[3,4-b]pyridine-5-carbonitriles.

Synthesis, characterization, and molecular structure investigation of new tetrahydrobenzo[b]thiophene-based Schiff bases: A combined experimental and theoretical study

“…In light of these findings and due to our interest in the synthesis of new heterocyclic compounds [50][51][52][53], in this paper, we wish to report the synthesis of some new heterocyclic Schiff bases derived from tetrahydrobenzo [b] thiophenes 3a-3e by condensation reaction of 2-amino-4, 5, 6, 7tetrahydrobenzo[b]thiophene-3carbonitrile 1 with aromatic aldehydes 2a-2e in dimethylformamide (DMF) containing ZnCl2 (Scheme 1). DFT calculations were also employed to identify the obtained stereoisomers.…”