Micromass q tof micro synapt high definition mass spectrometer

Starting materials, reagents, and solvents were purchased from commercial suppliers and used without further purification, unless otherwise stated. Anhydrous tetrahedrofuran (THF) and CH₂Cl₂ were obtained by distillation over sodium wire or CaH₂, respectively. All non-aqueous reactions were run under a nitrogen atmosphere with exclusion of moisture from reagents, and all reaction vessels were oven-dried. The progress of reactions was monitored by TLC on SiO₂. Spots were visualized by their quenching of the fluorescence of an indicator admixed to the SiO₂ layer, or by dipping into phosphomolybdic acid ethanol solution followed by heating. SiO₂ for flash chromatography was of 200–300 mesh particle size, and an EtOAc/PE mixture or gradient was used unless stated otherwise. ¹H NMR spectra were recorded at a spectrometer frequency of 400 MHz, ¹³C NMR spectra at 101 MHz. Chemical shifts are reported in δ (ppm) using the δ 0 signal of tetramethylsilane (TMS) as internal standard. High resolution mass spectra were performed using a Bruker ESI-TOF high-resolution mass spectrometer and Waters Micromass Q-TOF micro Synapt high definition mass spectrometer.

Accurate mass and MS/MS measurements were obtained using a detector with a dual electrospray ionization (ESI) probe and a Micromass Q-TOF micro Synapt High-Definition Mass Spectrometer (Waters, Milford, USA). The mass spectra were acquired in positive ionization modes (ESI⁺), and the optimal conditions of analysis were set as follows: the source temperature 110°C; the temperature and flow of the desolvation gas 350°C and 600 L/h, respectively; the capillary voltage 2.5 kV for the negative mode; the sampling cone voltage 30 V; the capillary voltage 3.0 kV for the positive mode; extraction cone voltage 45 V; cone gas flow 50 L/h; and collision energy 6.0 eV. All analyses were performed using the LockSpray interface to ensure accuracy and reproducibility. The Q-TOF Premier sample collection was 0.1 s with a 0.02 s scan interval delay, and the first resolving quadrupole was performed in the wide-pass mode (100–1,500 Da). Leucine encephalin amide acetate (200 pg/µL) was used as the lock mass ([M+H]⁺ = 555.2931, [M−H]⁻ = 553.2775) with a flow rate of 20 µL/min.