Design, microwave-assisted synthesis and in silico docking studies of new 4H-pyrimido[2,1-b]benzothiazole-2-arylamino-3-cyano-4-ones as possible adenosine A2B receptor antagonists

1105-1113A series of new 4H-pyrimido[2,1-<i style="mso-bidi-font-style: normal">b]benzothiazole-2-arylamino-3-cyano-4-ones <b style="mso-bidi-font-weight: normal">6a-g have been designed and synthesized by the application of microwave-assisted organic synthesis (MAOS) technique. <i style="mso-bidi-font-style: normal">In silico docking studies have been carried out to gain an insight into the hypothetical binding motif of the title compounds using a homology model of A2B adenosine receptor employing GOLD (CCDC, 4.0.1 version) software. The binding modes are proposed on the basis of molecular docking studies. </span

Crystallography, Molecular Modeling, and COX-2 Inhibition Studies on Indolizine Derivatives

The cyclooxygenase-2 (COX-2) enzyme is an important target for drug discovery and development of novel anti-inflammatory agents. Selective COX-2 inhibitors have the advantage of reduced side-effects, which result from COX-1 inhibition that is usually observed with nonselective COX inhibitors. In this study, the design and synthesis of a new series of 7-methoxy indolizines as bioisostere indomethacin analogues (5a–e) were carried out and evaluated for COX-2 enzyme inhibition. All the compounds showed activity in micromolar ranges, and the compound diethyl 3-(4-cyanobenzoyl)-7-methoxyindolizine-1,2-dicarboxylate (5a) emerged as a promising COX-2 inhibitor with an IC50 of 5.84 µM, as compared to indomethacin (IC50 = 6.84 µM). The molecular modeling study of indolizines indicated that hydrophobic interactions were the major contribution to COX-2 inhibition. The title compound diethyl 3-(4-bromobenzoyl)-7-methoxyindolizine-1,2-dicarboxylate (5c) was subjected for single-crystal X-ray studies, Hirshfeld surface analysis, and energy framework calculations. The X-ray diffraction analysis showed that the molecule (5c) crystallizes in the monoclinic crystal system with space group P 21/n with a = 12.0497(6)Å, b = 17.8324(10)Å, c = 19.6052(11)Å, α = 90.000°, β = 100.372(1)°, γ = 90.000°, and V = 4143.8(4)Å3. In addition, with the help of Crystal Explorer software program using the B3LYP/6-31G(d, p) basis set, the theoretical calculation of the interaction and graphical representation of energy value was measured in the form of the energy framework in terms of coulombic, dispersion, and total energy