0000000000202926
AUTHOR
Ahmed A. M. Sarhan
showing 6 related works from this author
A novel synthetic approach to pyran-2,4-dione scaffold production: Microwave-assisted dimerization, cyclization, and expeditious regioselective conve…
2020
Abstract Here, we report a novel, green, simple, low-cost, and rapid methodology for the high-yield production of pyran-2,4-dione scaffolds under microwave irradiation. Regio- and stereoselective conversions of β-diketone systems into β-enaminones were achieved using 18 primary amines and four amino acid esters. Microwave-assisted further cyclization of 3-(β-substitutedvinyl)-6-phenyl-pyran-2,4-dione into 3-benzoyl-4,7-diphenyl-2H,5H-pyrano[4,3-b]pyran-2,5-dione via reaction with ethyl benzoyl acetate.
Intramolecular Hydrogen Bond, Hirshfeld Analysis, AIM; DFT Studies of Pyran-2,4-dione Derivatives
2021
Intra and intermolecular interactions found in the developed crystals of the synthesized py-ron-2,4-dione derivatives play crucial rules in the molecular conformations and crystal stabili-ties, respectively. In this regard, Hirshfeld calculations were used to quantitatively analyze the different intermolecular interactions in the crystal structures of some functionalized py-ran-2,4-dione derivatives. The X-ray structure of pyran-2,4-dione derivative namely (3E,3′E)-3,3′-((ethane-1,2-diylbis(azanediyl))bis(phenylmethanylylidene))bis(6-phenyl-2H-pyran-2,4(3H)-dione) was determined. It crystallized in the monoclinic crystal system and C2/c space group with unit cell parameters: a = 14.0869(4) …
Synthesis and X-ray Crystal Structure of New Substituted 3-4′-Bipyrazole Derivatives. Hirshfeld Analysis, DFT and NBO Studies
2021
A new compounds named 3-4′-bipyrazoles 2 and 3 were synthesized in high chemical yield from a reaction of pyran-2,4-diketone 1 with aryl hydrazines under thermal conditions in MeOH. Compound 2 was unambiguously confirmed by single-crystal X-ray analysis. It crystalizes in a triclinic crystal system and space group P-1. Its crystal structure was found to be in good agreement with the spectral characterizations. With the aid of Hirshfeld calculations, the H…H (54.8–55.3%) and H…C (28.3–29.2%) intermolecular contacts are the most dominant, while the O…H (5.8–6.5%), N…H (3.8–4.6%) and C…C (3.0–4.9%) are less dominant. The compound has a polar nature with a net dipole moment of 6.388 Debye. The …
Synthesis of C2-Symmetrical Bis-(β-Enamino-Pyran-2,4-dione) Derivative Linked via 1,6-Hexylene Spacer: X-ray Crystal Structures, Hishfeld Studies and…
2021
The synthesis of C2-symmetrical bis(β-enamino-pyran-2,4-dione) derivative 3 connected via 1,6-hexylene linker was reported for the first time. X-ray structures and Hirshfeld studies of the new bis- β-enamino-pyran-2,4-dione derivative 3 along with two structurally related pyran-2,4-dione derivatives 2a,b were discussed. A comparative analysis of the different intermolecular contacts affecting the crystal stability was presented. Generally, the H…H, O…H, and H…C interactions are common in all compounds and are considered the most abundant contacts. In addition, DFT calculations were used to compute the electronic properties as well as the 1H and 13C NMR spectra of the studied systems. All co…
Straightforward One-Pot Synthesis of New 4-Phenyl-1,2,5,6-tetraazafluoranthen-3(2H)-one Derivatives: X-ray Single Crystal Structure and Hirshfeld Ana…
2022
A straightforward one-pot route for the synthesis of a new 4-phenyl-1,2,5,6-tetraazafluoranthen-3(2H)-one is reported form the direct hydrazinolysis of triketo ester and hydrazine hydrate in ethanol. 4-Phenyl-1,2,5,6-tetraazafluoranthen-3(2H)-one was subjected to aza-Michael addition and N-alkylation on reaction with a set of alkylating agents in the presence of K2CO3. Hydrazinolysis of 4-phenyl-1,2,5,6-tetraazafluoranthen-3(2H)-one ester to hydrazide and conversion of hydrazide to thiosemicarbazide were successful. X-Ray single crystals analysis and 1H, 13C NMR were used for unambiguous structure confirmation. The O…H, N…H, C…N and C…C in 2, and the N…H, …
Base-Controlled Regiospecific Mono-Benzylation/Allylation and Diallylation of 4-Aryl-5-indolyl-1,2,4-triazole-3-thione : Thio-Aza Allyl Rearrangement
2023
The regiospecific S-benzylation/allylation of two 4-aryl-5-indolyl-1,2,4-triazole-3-thione precursors was carried out using Et3N as a base. Allyl group migration from exocyclic sulfur to the triazole nitrogen (N3) was successfully achieved in a short time via thermal fusion without the need for any catalyst. The allylation of indole nitrogen, along with exocyclic sulfur or triazole nitrogen (N3), was carried out using K2CO3 as stronger base. S,N-Diallylated products were converted to N,N-diallylated analogues using a simple fusion approach. Structural analyses of the two newly synthesized hybrids 2b and 5b investigated via the X-ray diffraction of a single crystal combined with Hirshfeld ca…