Agilent 6520 accurate mass q tof lc ms spectrometer

Lenalidomide (1) was purchased from AstaTech and used as received. VHL ligand (26) was purchased from Abosyn and used as received. GMP and GDP were purchased from ChemImpex and used as received. All solvents and reagents were used without further purification. Yields refer to chromatographically and spectroscopically (¹H NMR) homogeneous materials, unless otherwise stated. Reactions were monitored by thin-layer chromatography (TLC) carried out on 0.25-mm SiliCycle silica gel plates (60F-254) using UV-light (254 nm). Flash chromatography was performed using SiliaFlash P60 silica gel. Analytical RP-HPLC was performed using an Agilent 1260 Infinity HPLC equipped with a ZORBAX Eclipse XDB-C18 column (4.6 × 150 mm; 5 μm) at a flow rate of 1 mL/min, with detection at 214 and 254 nm. Semi-preparative HPLC was carried out on Agilent 1260 Infinity HPLC equipped with a PrepHT XDB-C18 column (21.2 × 150 mm; 5 μm) at a flow rate of 18 mL/min using 95% water as a mobile phase and detection at 254 nm and 214 nm. NMR spectra were performed on a 300 MHz Bruker instrument and calibrated using a solvent peak as an internal reference. Spectra were processed using MestReNova software. Mass spectrometry (HRMS) was performed using an Agilent 6520 Accurate-Mass Q-TOF LC/MS spectrometer using ESI ionization with less than 5-ppm error for all HRMS analyses.