Jnm la500 spectrometer

Melting points were determined
in open glass capillaries with a
Gallenkamp apparatus. Elemental analyses were carried out at the Microanalytical
Center of Cairo University, Giza, Egypt. Infrared spectra were recorded
as potassium bromide disks on a Pye Unicam SP 3-300 and Shimadzu FTIR
8101 PC infrared spectrophotometer. NMR spectra were recorded on a
JEOL JNM-LA500 spectrometer, operating at 500 MHz for ¹H NMR, and 125.65 MHz for ¹³C NMR. Chemical shifts were
reported downfield from TMS (= 0) for ¹H NMR. For ¹³C NMR, chemical shifts were reported in the scale relative
to the solvent used as an internal reference. Mass spectra (EI) were
obtained at 70 eV with a type Shimadzu GCMQP 1000 EX spectrometer.
Analytical thin-layer chromatography was performed using precoated
silica gel 60,778 plates (Fluka), and the spots were visualized with
UV light at 254 nm.

¹H, ¹³C, and ¹⁹F NMR spectra (JEOL JNM-LA 500
spectrometer, 500, 126, and 376 MHz,
respectively) were recorded with tetramethylsilane used as an internal
standard. Melting points were determined using a Büchi (Model
M565) automated melting point system (temperature measurement accuracy
is 0.1 °C). High-resolution mass spectrometry was performed by
the Elemental Analysis Section of Osaka University. Thin-layer chromatography
(TLC) was carried out on E. Merck 0.25 mm pre-coated glass-backed
plates (60 F₂₅₄). Development was accomplished using 5%
phosphomolybdic acid in ethanol with heating or visualized by UV light
where feasible. Column chromatography was performed with SiO₂ (Silica Flash F60, 230–400 mesh). All solvents and reagents
were used as received.