Monowave 300 microwave reactor

Starting reagents were purchased from commercial sources and were used without any additional purification. Enaminones 2 were prepared according to the literature procedures [37 (link)]. Microwave reactions were conducted in a Monowave 300 Microwave Reactor (Anton Paar GmbH, Graz, Austria). Column chromatography was performed using silica gel (230–400 mesh) and mixtures in different proportions of ethyl acetate with hexane as the mobile phase. Melting points were determined on a SMP-10 apparatus (Barloworld Scientific Limited, Stone, UK). ¹H NMR spectra were recorded on a 400 MHz spectrometer (Bruker, 100 MHz for ¹³C NMR) and referenced to the residual signals of the solvent (for ¹H and ¹³C). Chemical shifts are reported in parts per million (δ/ppm). Coupling constants are reported in Hertz (J/Hz). The peak patterns are indicated as follows: s, singlet; d, doublet; t, triplet; q, quadruplet; m, multiplet; dd, doublet of doublets and td, triplet of doublets. Low resolution mass spectra were recorded with an LCMS-8040 triple quadrupole liquid chromatograph mass-spectrometer (Shimadzu corp., Tokyo, Japan). The reaction progress was monitored by TLC and the spots were visualized under UV light (254 or 365 nm). Elemental analysis was performed on a EuroVector EA-3000 instrument (EuroVector S.p.A., Milan, Italy).

The chemicals and reagents for this study were of analytical reagents and supplied by Sigma Aldrich. Solvents used were purified by the known standard methods. Thin layer chromatography (TLC) experiments were carried out on precoated silica gel plates purchased from Merck Kiesel gel 60F 254, BDH. Digital Stuart SMP3 electric melting point equipment was used to measure the melting points of the compounds. The microwave irradiation reactions (10 mL borosilicate glass vials) were performed using Anton Paar (monowave 300) microwave reactor. Mass spectrometry (EI, 70 eV) measurements were performed on a GC-2010 Shimadzu GCM spectrometer. Perkin-Elmer 293 spectrophotometer instrument was used for the IR measurements (KBr pellets, cm⁻¹). ¹H- and ¹³C-NMR measurements had been performed on a Varian Mercury 300 MHz spectrometer. Deuterated DMSO solutions of the samples with TMS as internal standard were used for the analysis. The microanalytical (CHN) analyses were carried out using a Perkin-Elmer analyzer (CHN-2400). Accuracy of the data were within ± 0.3% of calculated values.

FeCl₃ × 6 H₂O (75 mg, 0.28 mmol), sodium
citrate
hydrate (80 mg, 0.27 mmol), and 1280 MBq of ⁶⁸GaCl₃ in HCl (0.05 M, 4 mL) were dissolved in water (5 mL) in a
microwave-adapted flask, followed by addition of 1 mL of hydrazine
hydrate. The solution was ramped to 120 °C over 54 s and held
at this temperature for 10 min (240 W) in a Monowave 300 microwave
reactor equipped with an internal temperature probe and an external
IR probe (Anton Paar, GmbH, Ostfildern-Scharnhausen, Germany). The
reaction mixture was then cooled to 60 °C, and the ⁶⁸Ga-IONP-citrate product was purified by passing the mixture through
a PD-10 column to eliminate excess small reagents, including all unincorporated
radioisotopes. This purification process provided 9 mL of ⁶⁸Ga-IONP-citrate with a total activity of 781 MBq (measured 40 min
after starting the reaction), with a radiolabeling yield of 92%.