Synthesis and Structure of O-Ethyl S-Hydrogen Isoquinolin-1-ylcarbonothioimidate

O-Ethyl S-hydrogen isoquinolin-l-ylcarbonothioimidate was synthesized and its structure was characterized by IR, MS, ^1H NMR, elemental analysis and single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c with a = 10.9471（19）, b = 9.3968（17）, c = 10.6125（19） A, β = 100.761 （3）°, V = 1072.5（3） A^3, Z = 4, Dc = 1.439 g/cm^3, F（000） = 488 and μ = 0.279 mm^-1. A total of 7763 reflections were collected, of which 2090 were unique. The structure was refined to the final R = 0.0322 and wR = 0.0882 for 2016 observed reflections with Ⅰ 〉 2σ（Ⅰ）. The crystal structure shows that there are intramolecular N-H…S hydrogen bonds and π-π stacking interactions between adjacent molecules.

RESEARCH ON CONFORMATION OF CAPROLACTAM AND ITS ALKYL DERIVATIVES

Caprolactam is treated with dimethyl sulfate in benzene medium under conditions of various molar ratios to yield two different methylatcd products. The homogeneous reaction of caprolactam with dimethyl sulfate without any medium can only givc one methylated derivative. In a similar condition to that mentioned above, the reaction of caprolactam with diethylsulfate forms also one product, O-ethyl caprolactim. In this articlc NMR spectrum is applied to further identify the molecular structures of two methylated derivatives held by predecessors, and, applied the chemical shift reagent to induce the NMR and combined the field scanning and decoupling method to confirm the classification of signals, as a consequence the preferred conformation of caprolactam and its alkyl derivatives are proposed.

Synthesis, Crystal Structure and Biological Activites of Rotenone O-Alkyl Oximes

A series of rotenone O-alkyl oxime derivatives was designed and synthesized. Their structures were confirmed by elemental analyses, Fourier transform infrared（FTIR） and 1H NMR spectral studies, and the typical crystal structure of rotenone O-ethyl oxime（3b） was determined by X-ray diffraction. The preliminary biological activities of the new compounds were evaluated. The results of bioassays indicate that the title compounds exhibit moderate insecticidal and bactericidal activities. Among the synthesized compounds, compound 3q exhibited 90.0% mortality against M. separata at 1000 μg/mL. Compounds 3b and 3g exhibited both 90.0% inhibition rate against R. solani at 500 μg/mL, respectively.

The correlation between molecular structure parameters of O-ethyl N-isopropyl phosphoro(thioureido)thioates and their retention data in RP-HPLC

A retention prediction system(RPS)of seven O-ethyl N-isopropyl phosphoro(thioureido)- thioates in reversed phase HPLC was investigated.The system is based on the solvent selectivity triangle concept.Three molecular structure parameters(hydrophobicity Ⅱ,substituent length L, and substituent maximum width B_5)were used to describe the quantitative structure-retention relation- ships.With these quantitative relationships,the retention behaviours of other eight homologs for different mobile phase composition were predicted.The predicted values were consistent with the measured values within relative error of 10%,which means that it is possible to apply the reported method to predict retention values for qualitative purposes for different mobile phase compositions.

Computer-assisted retention prediction system in reversed-phase HPLC for O-ethyl O-aryl N-isopropyl phosphoramidothioates

A computer-assisted retention prediction system (RPS) of fifteen O-ethyl O-aryl N-iso- propyl phosphoramidothioates (1) in reversed-phase HPLC was investigated. The system is based on the use of four physicochemical parameters (hydrophobicity , electric effect σ, field effect F and steric effect ) which is closely related to the retention mechanism in reversed-phase HPLC. The system was evaluated by comparing the measured retention data with the predicted ones. The predicted values were consistent with the measured values within a relative error of 11.5%.