Hp 5 ms capillary

Unless stated otherwise, solvents were evaporated at 40 °C/2 kPa and compounds were dried at 13 Pa. Analytical TLC was performed on silica gel 60 F₂₅₄ plates (Merck KGaA, Darmstadt, Germany). The NMR spectra were measured on an FT NMR spectrometer (Bruker Avance II 500) in DMSO-d₆ (¹H at 500 MHz and ¹³C at 125.7 MHz), referenced to the residual solvent signal, chemical shift are expressed in parts per million, ppm, and interaction constants J in Hz. GC/MS analyses were measured using a 6,890 N gas chromatograph (Agilent, Santa Clara, CA, USA) attached to a quadrupole mass detector. A HP-5 ms capillary (30 m × 0.25 mm; 0.25 μm; Agilent) was used for the analyses. The carrier gas was helium with a flow rate of 1 mL/min. The EI mass spectra were measured on a GCT Premier (Waters) OA-TOF GC mass spectrometer. The elemental composition of the prepared compounds was determined using a PE 2400 Series II CHNS/O Elemental Analyzer (Perkin Elmer, USA, 1999). Melting points were determined on a Stuart SMP3 Melting Point Apparatus and are uncorrected. Compounds A12 and B12 were prepared according to the literature (Schostarez, 1992 ). Compounds A1 and B1 were purchased from Sigma-Aldrich.