Trifluoromethanesulfonic anhydride → Trifluoromethanesulfonic acid 5-(1-methyl-1H-pyrazol-4-yl)-quinolin-6-yl ester

Participants

Reaction Conditions

Reaction Steps

5-(1-Methyl-1H-pyrazol-4-yl)-quinolin-6-ol (2.9 g, 12.89 mmol) was dissolved in pyridine (30 mL) and the mixture was cooled to 0° C. in an ice bath under a flow of nitrogen. Tf2O (2.6 mL, 15.47 mmol) was added slowly. Then the reaction mixture was stirred at room temperature for 5 hours. The mixture was partitioned between dichloromethane (50 mL) and saturated aqueous NaHCO3 (50 mL). The organic phase was separated and washed with brine (5×30 mL). The organic phase was dried over Na2SO4, filtered and concentrated. The residue was purified by column chromatography to give 3.9 g of Trifluoromethanesulfonic acid 5-(1-methyl-1H-pyrazol-4-yl)-quinolin-6-yl ester (84% yield): 1H NMR (300 MHz, CDCl3) δ: 4.05 (s, 3H), 7.48˜7.44 (m, 1H), 7.69˜7.61 (m, 3H), 8.18 (d, 1H), 8.32 (m, 1H), 8.98 (m, 1H); MS (m/z) 358 [M+H]+.

Provenance & Evidence