Prakash S. Nayak

FT-IR, molecular structure, first order hyperpolarizability, MEP, HOMO and LUMO analysis and NBO analysis of 4-[(3-acetylphenyl)amino]-2-methylidene-4-oxobutanoic acid.

4-[(3-Acetylphenyl)amino]-2-methylidene-4-oxobutanoic acid is synthesized and the structure of the compound was confirmed by IR, (1)H NMR and single crystal X-ray diffraction studies. FT-IR spectrum of 4-[(3-acetylphenyl)amino]-2-methylidene-4-oxobutanoic acid was recorded and analyzed. The crystal structure is also described. The vibrational wavenumbers were computed using HF and DFT methods are assigned with the help of potential energy distribution analysis. The NH stretching frequency is red shifted in the IR spectrum with a strong intensity from the computed frequency, which indicates the weakening of the NH bond resulting in proton transfer to the neighboring oxygen atom. The first hyperpolarizability and infrared intensities are also reported. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. The HOMO and LUMO analysis are used to determine the charge transfer within the molecule. Molecular electrostatic potential map was performed by the DFT method. The geometrical parameters of the title compound obtained from XRD studies are in agreement with the calculated (DFT) values.

Synthesis, structural and vibrational investigation on 2-phenyl-N-(pyrazin-2-yl)acetamide combining XRD diffraction, FT-IR and NMR spectroscopies with DFT calculations

The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of 2-phenyl-N-(pyrazin-2-yl)acetamide have been investigated experimentally and theoretically using Gaussian09 software package. The title compound was optimized by using the HF/6-31G(6D,7F) and B3LYP/6-31G(6D,7F) calculations. The geometrical parameters are in agreement with the XRD data. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. Gauge-including atomic orbital (1)H-NMR chemical shifts calculations were carried out and compared with experimental data. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. Molecular electrostatic potential was performed by the DFT method. First hyperpolarizability is calculated in order to find its role in non linear optics. From the XRD data, in the crystal, molecules are held together by strong C-H⋯O and N-H⋯O intermolecular interactions.

FT-IR, molecular structure, first order hyperpolarizability, NBO analysis, HOMO and LUMO and MEP analysis of 1-(10H-phenothiazin-2-yl)ethanone by HF and density functional methods.

FT-IR spectrum of 1-(10H-phenothiazin-2-yl)ethanone was recorded and analyzed. The equilibrium geometry, bonding features and harmonic vibrational wavenumbers were investigated with the help of HF and DFT methods. The normal modes are assigned with the help of potential energy distribution analysis. The observed vibrational wavenumbers were compared with the calculated results. The geometrical parameters of the title compound obtained from XRD studies are in agreement with the calculated (DFT) values. The first hyperpolarizability value is also reported. Natural bond orbital analysis confirms the presence of intra-molecular charge transfer and hydrogen bonding interaction. The HOMO-LUMO gap explains the charge transfer interaction taking place within the molecule. The N-H stretching frequency is red shifted in the IR spectrum with a strong intensity from the computed frequency, which indicates weakening of the N-H bond resulting in proton transfer to the neighboring units. From the MEP analysis it is evident that the negative charge covers the carbonyl and benzene and the positive region is over the NH group.

Infrared spectrum, NBO, HOMO-LUMO, MEP and molecular docking studies (2E)-3-(3-nitrophenyl)-1-[4-piperidin-1-yl]prop-2-en-1-one.

FT-IR spectrum of (2E)-3-(3-nitrophenyl)-1-[4-piperidin-1-yl]prop-2-en-1-one was recorded and analyzed. The vibrational wavenumbers were computed using HF and DFT quantum chemical calculations. The data obtained from wavenumber calculations are used to assign IR bands. Potential energy distribution was done using GAR2PED software. The geometrical parameters of the title compound are in agreement with the XRD results. NBO analysis, HOMO-LUMO, first and second hyperpolarizability and molecular electrostatic potential results are also reported. The possible electrophile attacking sites of the title molecule is identified using MEP surface plot study. Molecular docking results predicted the anti-leishmanic activity for the compound.

N-(2,6-Dichloro­phen­yl)-2-(naphthalen-1-yl)acetamide

In the title compound, C18H13Cl2NO, the naphthalene ring system and the benzene ring form dihedral angles of 74.73 (13) and 62.53 (16)°, respectively, with the acetamide grouping [maximum deviation = 0.005 (3) Å]. The naphthalene ring system forms a dihedral angle of 75.14 (13)° with the benzene ring. In the crystal, molecules are linked by N—H⋯O hydrogen bonds, forming C(4) chains propagating in [010]. The O atom also accepts two C—H⋯O interactions.

N-(1,3-Thia­zol-2-yl)-2-(2,4,6-trimethyl­phen­yl)acetamide

In the title compound, C14H16N2OS, the thiazole ring is essentially planar (r.m.s. deviation = 0.005 Å) and it forms a dihedral angle of 75.21 (8)° with the benzene ring. In the crystal, molecules are linked into inversion dimers by pairs of N—H⋯N hydrogen bonds to generate R 2 2(8) loops.

Design and synthesis of novel heterocyclic acetamide derivatives for potential analgesic, anti-inflammatory, and antimicrobial activities

A new series of heterocyclic amides were synthesized by the reaction of heterocyclic amines with substituted phenylacetic acids 1 in the presence of EDC.HCl as a coupling agent. The newly synthesized compounds were characterized by IR, NMR, mass spectral, and elemental analysis. All the synthesized compounds were evaluated for their in vivo analgesic, anti-inflammatory, and in vitro antimicrobial activities. Among the tested acetamides, the compounds 2a, 3b, 4d, 4e, and 4f showed potential anti-inflammatory and analgesic activities. The compounds which exhibited good anti-inflammatory activity were docked to mouse COX-1 (PDB ID: 2CZT) and COX-2 (PDB ID: 3LN1) enzymes to predict their putative interactions. The compound 2-(2-Bromophenyl)-N-(pyrazin-2-yl)acetamide (4f) emerged as most potent molecule with synergistic anti-inflammatory, analgesic, and antimicrobial properties.

N-(1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-2-[4-(methyl­sulfan­yl)phen­yl]acetamide

In the title compound, C20H21N3O2S, the 2,3-dihydro-1H-pyrazole ring is nearly planar (r.m.s. deviation = 0.023 Å) and forms dihedral angles of 16.96 (6) and 38.93 (6)° with the benzene and phenyl rings, respectively. The dihedral angle between the benzene and phenyl rings is 55.54 (6)°. The molecular conformation is consolidated by an intramolecular C—H⋯O hydrogen bond, which forms an S(6) ring. In the crystal, inversion dimers linked by pairs of N—H⋯Op (p = pyrazole) hydrogen bonds generate R 2 2(10) loops. The dimers are linked by C—H⋯O hydrogen bonds into sheets lying parallel to (100).

Halogenated C,N‐diarylacetamides: molecular conformations and supramolecular assembly

The structures of four halogenated N,2-diarylacetamides are reported and compared with a range of analogues. N-(4-Chloro-3-methylphenyl)-2-phenylacetamide, C(15)H(14)ClNO, (I), and N-(4-bromo-3-methylphenyl)-2-phenylacetamide, C(15)H(14)BrNO, (II), are isostructural in the space group P-1. The molecules of (I) and (II) are linked into chains of rings by a combination of N-H...O and C-H...π(arene) hydrogen bonds. The molecules of N-(4-chloro-3-methylphenyl)-2-(2,4-dichlorophenyl)acetamide, C(15)H(12)Cl(3)NO, (III), and N-(4-bromo-3-methylphenyl)-2-(2-chlorophenyl)acetamide, C(15)H(13)BrClNO, (IV), are linked into simple C(4) chains by N-H...O hydrogen bonds, but significant C-H...π(arene) interactions are absent. The N-aryl groups in compounds (III) and (IV) adopt a different orientation, by ca 180°, from that of the corresponding groups in compounds (I) and (II), but otherwise the conformations of (I)-(IV) are very similar. Comparisons are drawn between compounds (I) and (IV) and a range of analogues of the type R(1)CH(2)CONHR(2), where R(2) represents a halogenated aryl ring and R(1) represents either another halogenated aryl ring or a naphthalen-1-yl unit.

2-(3,4-Dichloro­phen­yl)-N-(1,3-thia­zol-2-yl)acetamide

In the title compound, C11H8Cl2N2OS, the mean plane of the dichlorophenyl ring is twisted by 79.7 (7)° from that of the thiazole ring. In the crystal, molecules are linked via pairs of N—H⋯N hydrogen bonds, forming inversion dimers which stack along the a-axis direction.