IR spectra
were recorded as a dry film on a Bruker Alpha II spectrometer or a
Bruker Invenio S spectrometer equipped with an HTS-XT accessory. UV
spectra were recorded as methanol solutions on a Varian Cary 50-Bio
UV/vis spectrophotometer. NMR spectra were recorded at 25 °C
on a 600 MHz Bruker Avance III HD spectrometer, equipped with a triple
resonance 5 mm CPP TCI cryo-probe, and operating at a frequency of
600.0 MHz for the 1H nucleus and 150.9 MHz for the 13C nucleus. All 2D NMR experiments were acquired with non-uniform
sampling (NUS) set to 40% (for 1H–1H
detected experiments) or 35% (for 1H–13C detected experiments). 1H and 13C NMR chemical
shifts were referenced to the solvent peak for DMSO-d6 at δH 2.50 δC 39.50.
NMR FID processing and data interpretation was done using MestReNova
software, version 14.2. High-resolution mass spectra were recorded
on an Agilent 6545 Accurate-Mass Q-TOF LC/MS system (1290 Infinity
II) equipped with a dual AJS ESI source. Semi-preparative scale HPLC
purification was performed with either a Gilson HPLC purification
system equipped with a GX-281 liquid handler, a 322-binary pump, and
a 172-photodiode array detector or a Waters Prep LC system, equipped
with a Delta 600 pump and a 996-photodiode array detector. All solvents
used for chromatography, UV, and MS were HPLC grade, and the H2O was Millipore Milli-Q PF filtered.
were recorded as a dry film on a Bruker Alpha II spectrometer or a
Bruker Invenio S spectrometer equipped with an HTS-XT accessory. UV
spectra were recorded as methanol solutions on a Varian Cary 50-Bio
UV/vis spectrophotometer. NMR spectra were recorded at 25 °C
on a 600 MHz Bruker Avance III HD spectrometer, equipped with a triple
resonance 5 mm CPP TCI cryo-probe, and operating at a frequency of
600.0 MHz for the 1H nucleus and 150.9 MHz for the 13C nucleus. All 2D NMR experiments were acquired with non-uniform
sampling (NUS) set to 40% (for 1H–1H
detected experiments) or 35% (for 1H–13C detected experiments). 1H and 13C NMR chemical
shifts were referenced to the solvent peak for DMSO-d6 at δH 2.50 δC 39.50.
NMR FID processing and data interpretation was done using MestReNova
software, version 14.2. High-resolution mass spectra were recorded
on an Agilent 6545 Accurate-Mass Q-TOF LC/MS system (1290 Infinity
II) equipped with a dual AJS ESI source. Semi-preparative scale HPLC
purification was performed with either a Gilson HPLC purification
system equipped with a GX-281 liquid handler, a 322-binary pump, and
a 172-photodiode array detector or a Waters Prep LC system, equipped
with a Delta 600 pump and a 996-photodiode array detector. All solvents
used for chromatography, UV, and MS were HPLC grade, and the H2O was Millipore Milli-Q PF filtered.