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The present communication deals with the conformational, vibrational spectroscopic analysis and molecular docking study of an important biorelevant molecule namely 5-Chloro-2-hydroxy-N-isobutyl-3-oxo-2,3-dihydrobenzofuran-2-carboxamide. We have recorded FTIR spectrum of the target molecule in the spectral range of 4000–400 cm−1 and this has been correlated with simulated spectra of the most stable conformer. Most of the theoretical frequencies showed good agreement with experimental frequencies and a few were modified. The theoretical computations on the target molecule have been performed at well-known DFT/B3LYP level. The 6-31++G(d,p) was incorporated as a conventional basis set during the complete computations. For normal modes analysis, the potential energy distributions of the most stable conformer were calculated by Molvib program. The NBO calculations were performed to ensure stability of electronic structure and to explore intermolecular interactions. Some important thermodynamical parameters have also been investigated. The effect of aqueous media revealed that target molecule becomes slightly more stable in water phase. HOMO-LUMO gap has been computed to be 4.19 eV. [ABSTRACT FROM AUTHOR]

A combined experimental and theoretical study is performed on DMSO solvated 7′-amino-1′,3′-dimethyl- 2,2′,4′-trioxo-1′,2′,3′,4′,4a′,8a′-tetrahydrospiro[indoline-3,5′-pyrano[2,3-d]pyrimidine]-6′-carbonitrile. The compound is studied by NMR, IR spectroscopy, and single crystal X-ray analysis. The crystal structure of the molecule is stabilized by intermolecular N-H…N, N-H…O, and C-H…π interactions. In the crystal, the molecules form hydrogen-bonded chains running along the b axis of the unit cell. In the present work, we have applied density functional theory (DFT) to explore the nonlinear properties of the molecule. The harmonic vibrational frequencies are calculated and compared with experimental FT-IR frequencies. The observed and calculated frequencies are found to be in good agreement. The calculated values of the HOMO-LUMO energy gap shows that a charge transfer occurs within the molecule. [ABSTRACT FROM AUTHOR]

The title compound, 2-amino-7,7-dimethyl-5-oxo-4-(pyridin-4-yl)-5,6,7,8-tetrahydro-4 Hchromene-3-carbonitrile was synthesized by multicomponent reaction at room temperature using commercially available urea as inexpensive and environmentally benign organo-catalyst. Its structure was determined by X-ray structure analysis. The crystals are monoclinic, sp. gr. C2/ c, a = 22.010(6), b = 11.0364(10), c = 17.147(4) Å, β = 130.37(4)°, Z = 8, R = 0.0433 for 2377 observed reflections. [ABSTRACT FROM AUTHOR]

Two carbonitrile compounds, 2-amino-4-(3-nitrophenyl)-5-oxo-4,5-dihydropyrano[3,2- c] chromene-3-carbonitrile ( I) and 2-amino-7,7-dimethyl-4-(4-nitrophenyl)-5-oxo-5,6,7,8-tetrahydro-4 H-chromene-3-carbonitrile ( II), were synthesized, and their crystal structures were determined by X-ray diffraction technique. The crystals are triclinic, a = 7.7970(12), 8.2171(7), b = 9.0390(10), 9.2238(7), c = 15.148(2), 14.5585(11) Å, α = 81.439(10)°, 74.895(6)°, β = 75.194(12)°, 87.392(6)°, γ = 76.151(11)°, 78.552(7)°, for I and II, respectively, Z = 2, sp. gr. P $$\overline 1$$. The pyran ring in both the compounds deviates significantly from planarity and adopts boat conformation. The crystal structure is stabilized by N-H···O and N-H···N hydrogen bonds. [ABSTRACT FROM AUTHOR]

We herein disclose a dual synthetic approach involving electrochemical and mechanochemical strategies for diversely functionalized 3-nitro-2-aryl-immidazo[1,2- a ]pyridines. Both methods offer a practical and straightforward alternative route for accessing this important class of biologically promising nitrogen-containing heterocycles. Significant advantages of the newly developed methods include mild and energy-efficient reaction conditions, avoidance of transition metal catalysts, external heating and additional oxidants, shorter reaction times, good to excellent yields, broad substrate scope, gram-scale applicability, operational simplicity, and eco-friendliness. Furthermore, a synthetic application was extended by successfully reducing synthesized 3-nitro-2-aryl-immidazo[1,2- a ]pyridines to their corresponding amino derivatives.

We herein report the exploration of an electrosynthetic strategy as a highly efficient and straightforward alternative protocol for accessing diversely substituted and biologically promising alkyl 2-hydroxy-3-oxo-2,3-dihydrobenzofuran-2-carboxylates through an electrorearranged difunctionalization of 4-hydroxycoumarins, involving the singlet oxygen insertion from molecular oxygen, at ambient temperature. The present method is notably more advantageous than the previously reported photochemical conversion regarding yields and reaction times, substrate scope and functional group tolerability, operational simplicity, and scalability.

This feature article summarises our recent contributions (2019-2023) in designing and developing a handful of promising organic transformations for accessing several diversely functionalised biologically relevant organic scaffolds, following the green chemistry principles, particularly focusing on the application of low-energy visible light, electrochemistry, ball-milling, ultrasound, and catalyst- and additive-free synthetic strategies.