New Synthetic Methods for 2‐Pyridone Rings

Abstract

For Abstract see ChemInform Abstract in Full Text.

Novel multitarget-directed tacrine derivatives as potential candidates for the treatment of Alzheimer’s disease

“…Presently, several natural compounds bearing pyridin-2(1 H )-ones (2-pyridones) structure have emerged with numerous pharmacological activities, such as AChEI, antioxidant and antitumour 128–130 , while many synthetic or semisynthetic clinical drugs also enclose those nontoxic moieties 131 . Therefore, Chand et al.…”

A dielectric and spectrophotometric study of the tautomerization of 2-hydroxypyridine and 2-mercaptopyridine in water

“…Indeed, this implies DRS provides a crucial relation between the s, and k f and k b . By combining eqn (11) and (13), the values of rate constants, k f , and k b are evaluated (see Table 3).…”

“…The real and imaginary dielectric spectra, obtained from the VNA were tted simultaneously using a non-linear least square method based on the Levenberg-Marquardt algorithm 85 in Origin 2018b according to the Debye equation, as shown below, 3*(n) ¼ 3 0 À i3 00 ¼ 3 a + D3/(1 + 2pins) (11) where, i ¼ OÀ1, n ¼ frequency (in GHz), 3 a ¼ high frequency dielectric permittivity, D3 ¼ 3 s À 3 a ¼ relaxation amplitude, 3 s ¼ static permittivity, s ¼ relaxation time of water (in ps). It is familiar that pure water conforms to eqn (11) (ref.…”

“…Indeed, 2Py is a heteroaromatic system to describe hydrogen-bonded DNA base pairs; 8 catalytic design element; 9 with potential for selfassembly platform of bidentate ligands 10 and blocks in synthesis. 11 Some of the nucleic acid bases exhibit the keto-enol tautomerism, in which proton transfer takes place between N and O sites of the molecules and may be one of the possible routes for the DNA and RNA mutations. [12][13][14] From the theoretical and experimental studies that have been reported, [15][16][17][18][19][20][21][22][23] it can be gleaned that in pyridine and pyrimidine substituted at 2-or 4-positions by tautomeric groups XH (X ¼ O or S) exist in lactam or thione forms rather than in lactim or thiol forms.…”

Poly (4-vinylpyridine) and polyaniline: As efficient and commercial available basic catalysts for the synthesis of N-amino-2-pyridones under thermal conditions or microwave irradiation

“…Namino-2-pyridoneshaveknown asusefulsynthetic intermediates and a versatile synthon for the synthesis of a variety of other nitrogen-containing heterocyclic compounds, such as β-lactams, piperidines, and indolizidine alkaloids [4]. The dienophiles have been reacted with diene portion of these molecules via Diels-Alder cycloaddition reactions, or one double bond of these molecules, may act as a dienophile and add to diene [5].There are few reported methods for the synthesis of N-amino-2-pyridones in the literature [6,7].These compounds were usually prepared in low yields by condensation of hydrazine with 2-pyrones followed by the loss of water [8,9]. The most common strategies involve the construction of arylidenemalononitriles, which are easily prepared by Knoevenagel condensation of aromatic aldehydes with malononitrile, and cyanoacetic acid hydrazide in the presence of piperidine as a base catalyst [7].Piperidine and pyridine were usually used as liquid base catalysts in condensation reactions [7,10].…”