Advance dpx400

The synthetic procedures and analysis were reproduced from the previously reported synthesis of JMC31 [21 (link)]. Electrospray ionization mass spectrometry (ESI-MS) was performed by an Agilent 1100 series liquid chromatograph system with an API-ES interface. Mass spectra were acquired in positive mode scanning over the mass range m/z of 150–1500. ¹H NMR and ¹³C NMR spectra were recorded on a Bruker Advance DPX400 operating at 400 MHz, using the residual signal of the deuterated solvent as the internal standard. The value of chemical shifts (δ) is given in ppm and coupling constants (J) are given in hertz (Hz). Splitting patterns are described as singlet (s), doublet (d), triplet (t), quartet (q), doublet of doublet (dd), and multiplet (m). The chemical purity of the final compound was determined using an Agilent 1260 Infinity instrument comprising a binary pump, an autosampler, a UV-DAD, and an ESI-MS detector. The chromatographic separation was performed with an Agilent Poroshell 120 EC-C18 column (4.6 mm × 100 mm, 2.7 μm), injecting 5 μL of the sample. Analyses were carried out with gradient elution, solvent A (0.1% formic acid in water), and solvent B (0.1% formic acid in acetonitrile), 90:10 to 10:90 over 6 min, at the flow rate of 2 mL/min, and a UV detector at 254 nm. The compound purity was ≥95.0%.

Melting points were recorded in Fisher-Johns melting point apparatus serial 4446 Fisher-Scientific company (Fisher-Scientific international Inc., Pittsbugh, PA, USA) and are uncorrected. Mass spectra were recorded, using the electron impact mode (70 or 20 eV) in a GCMS QP2010 Shimadzu HP 5971 spectrometer (Shimadzu Corporation, Kyoto, Japan). Elementary analyses were performed in a microanalyzer Fisons EA 1108 CHNS-O (Fison Instruments Ltd., Glasglow, UK) Infrared spectra were recorded on neat samples (NaCl disks), using a Shimadzu FT/IR-8101 Type A spectrometer (Shimadzu Corporation, Kyoto, Japan). NMR spectra were obtained in a Bruker Advance DPX-400 instrument at 400 MHz for ¹H NMR and 100 MHz for ¹³C NMR in CDCl₃ or MeOH-D₄ or (CD₃)₂CO (Bruker Corporation, Billerica, MA, USA). Proton chemical shifts are reported in ppm downfield from TMS as an internal reference, and carbon chemical shifts are reported in ppm relative to the center line of the CDCl₃ triplet (77.0 ppm). Optical rotations were measured in a Krüss Optronic P8000 polarimeter (A. Krüss Optronic GmbH, Hamburg, Germany), using a 0.5 dm cell. Moreover, [α]_D values are given in units of deg cm² g⁻¹, and concentration values are expressed in g/100 mL.