Hydrochloric Acid → 8-Bromo-2-(1-piperidin-4-yl-1H-pyrazol-4-yl)-quinoxaline

Participants

Reaction Conditions

Reaction Steps

A 1.2 M solution of HCl in EtOH (60 ml, 72 mmol) is added to 4-[4-(8-Bromo-quinoxalin-2-yl)-pyrazol-1-yl]-piperidine-1-carboxylic acid tert-butyl ester (Step 94.1, 1.98 g, 4.32 mmol) and the reaction mixture is heated at 50° C. for 12 h. After cooling, the yellow suspension is concentrated under vacuo and the residue is diluted with CH2Cl2, poured onto a saturated solution of NaHCO3 and extracted 3× with CH2Cl2. The combined organic layers are washed with water, brine, dried over Na2SO4, filtered and the filtrate is concentrated in vacuo. The residue is used without further purification in the next step, and afford the title compound as pale orange solid, Rt=0.802 min (Acquity HPLC BEH C18, 2.1×50 mm, 1.7 micron, detection 215 nM, 0.1 min 2% CH3CN in H2O, 2% to 100% CH3CN in H2O in 1.5 min, 0.4 min 100% CH3CN+0.1% TFA, flow rate 1.0 ml/min); MS: 358 (M+1, 79Br)+

Provenance & Evidence