Sodium Bicarbonate → 9-cyclopropyl-7-(2,6-dimethylpyridin-4-yl)-6-fluoroisothiazolo[5,4-b]quinoline-3,4(2H,9H)-dione

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Reaction Steps

A mixture of tert-butyl 7-bromo-9-cyclopropyl-6-fluoro-3,4-dioxoisothiazolo[5,4-b]quinoline-2(3H,4H,9H)-carboxylate (8, 22 mg, 0.048 mmol), 4-(2,6-Dimethylpyridyl)boronic acid (5, 23 mg, 0.12 mmol) and Pd (PPh3)4 (4 mg) in a solution of DMF (1 ml) and 1M NaHCO3 (0.22 ml) is sealed in a microwave reaction vessel with a stirrer. After filling with helium, the mixture is microwaved at 100 W, 130° C. for 10 minutes. The reaction is followed by LC-MS. The reaction mixture is filtered and the filtrate evaporated to dryness. The residue is washed with a solution of methanol and ethyl ether (5:95) (3×3 ml), and dried in vacuum yielding pure product 25. 1H NMR (300 MHz, DMSO-d6) δ 1.1-1.3 (m, 4H, —CH2—), 1.53 (s, 1H, —CH—), 2.47 (s, 6H, —CH3), 7.27 (s, 2H, Ar), 7.93, (d, 1H, Ar), 8.2 (d, 1H, Ar). 19F NMR (350 MHz, DMSO-d6) δ 125 (s, 1F). MS, m/z 382 (M+1).

Provenance & Evidence