In the title compound, C18H15ClFN3O4, the dihedral angle between the substituted pyridine ring and the oxadiazo­line ring is 9.73 (19)° and the acyl group is coplanar with the oxadiazo­line ring [O—C—N—C torsion angle = −2.1 (3)°]. Furthermore, the substituted benzene ring is almost orthogonal with the oxadiazo­line ring, the dihedral angle between them being 87.56 (18)°.

Optimal machining parameters can lead to considerable savings in manufacturing problems. In this paper, to deal with the nonlinear optimization problem of machining parameters which aims to minimize the unit production cost (UC) in parallel turnings, we propose a novel optimization approach which divides this complicated problem into several sub-problems. Then an estimation of distribution algorithm (EDA) is developed to search the optimal results for each sub-problem. Computer simulations show that the proposed approach is efficient in searching the optimal solutions to reduce significantly the unit production cost.

In this study, the alkaloids from Gynura Segetum (Lour.) Merr. were extracted based on the microwave-assisted supercritical CO2 extraction technique. Before extraction, the powder of Gynura Segetum (Lour.) Merr. was firstly soaked with ethanol-water solvent and irradiated by microwave The experimental conditions including ethanol concentration, soaking time and microwave irradiation time were carefully studied, and the best efficiency could be obtained when the ethanol concentration, soaking time and microwave irradiation time were respectively 90%, 10 h and 2 min. Meanwhile, a parallel experiment with only supercritical CO2 extraction was also carried out as a comparison. The results indicated the efficiency of microwave-assisted supercritical CO2 extraction method was better for extracting the alkaloids from Gynura Segetum (Lour.) Merr. samples. Finally, the structures of the crystals extracted from the Gynura Segetum (Lour.) Merr. were analyzed by infrared spectroscopy, and the seneciphylline was found as the main component of the crystals.