Synthesis and crystal structure of a novel substituted 1,4-dihydropyridine

The title compound, C15H16N2O3, was synthesized, characterized spectroscopically, and finally confirmed by X-ray diffraction studies. The compound crystallizes in the monoclinic space group P21/n with cell parameters a = 10.314(9) Å, b = 17.976(15) Å, c = 12.762(11) Å, β = 113.331(3)°, Z = 4, and V = 2173(3) Å3. The dihydropyridine ring in the structure is in a flattened-boat conformation. The 2-nitrophenyl ring is orthogonal to the 1,4-dihydropyridine ring. The structure exhibits an intermolecular hydrogen bond of the type C–H…O

Synthesis of monomethylated dimeric benzopyrans as HIV-1 and HIV-2 inhibitors: Part I

2197-2199Mono methylated dimeric coumarins have been synthesized by condensation of 6- or 8-methyl-4-hydroxycoumarins with different aromatic aldehydes. Twenty three compounds or the two series have been screened for anti -HIV activity against HIV-1 and HIV-2 strains

Method Development and Validation of a Stability-Indicating RP-HPLC Method for the Quantitative Analysis of Dronedarone Hydrochloride in Pharmaceutical Tablets

A simple, precise, and accurate HPLC method has been developed and validated for the quantitative analysis of Dronedarone Hydrochloride in tablet form. An isocratic separation was achieved using a Waters Symmetry C8 (100 x 4.6 mm), 5 μm particle size column with a flow rate of 1 ml/min and UV detector at 290 nm. The mobile phase consisted of buffer: methanol (40:60 v/v) (buffer: 50 mM KH2PO4 + 1 ml triethylamine in 1 liter water, pH=2.5 adjusted with ortho-phosphoric acid). The method was validated for specificity, linearity, precision, accuracy, robustness, and solution stability. The specificity of the method was determined by assessing interference from the placebo and by stress testing the drug (forced degradation). The method was linear over the concentration range 20–80 μg/ml (r2 = 0.999) with a Limit of Detection (LOD) and Limit of Quantitation (LOQ) of 0.1 and 0.3 μg/ml respectively. The accuracy of the method was between 99.2–100.5%. The method was found to be robust and suitable for the quantitative analysis of Dronedarone Hydrochloride in a tablet formulation. Degradation products resulting from the stress studies did not interfere with the detection of Dronedarone Hydrochloride so the assay is thus stability-indicating

Synthesis, characterization, crystal and molecular structure analysis of 2,6-dimethyl-3-acetyl-5-carbomethoxy-4-(3-nitrophenyl)-1,4-dihydropyridi ne

A novel unsymmetrical dihydropyridine, possessing carboxymethyl and carbomethoxy groups at C(3) and C(5), respectively, has been produced using a modified Hantzsch synthesis, under solvent free conditions, in a domestic microwave oven. The product obtained was characterized by spectroscopic techniques and finally confirmed by X-ray diffraction studies. The title compound C17H18N2O5 crystallizes in the monoclinic system in the space group P2(1)/c with cell parameters a = 12.860(2) angstrom, b = 7.4950(6) angstrom, c = 16.734(3) angstrom, beta = 94.436(3)degrees, Z = 4 and V = 1608.1(4) angstrom(3). The 1,4-dihydropyridine ring in the structure is in a flattened boat conformation. The molecule possesses a chiral center at C4. The 3-nitrophenyl ring is nearly orthogonal to the 1,4-dihydropyridine ring. The carbonyl groups at C3 and C5 are oriented in -antiperiplanar and +synperiplanar conformations, respectively. The structure exhibits both inter and intramolecular hydrogen bonds of the type N-H center dot center dot center dot O and C-H center dot center dot center dot O