Diisopropylamine → 9-Cyclopropyl-6-fluoro-7-(2-(pyridin-2-YL)ethynyl)isothiazolo[5,4-B]quinoline-3,4(2H,9H)-dione

Participants

Reaction Conditions

Reaction Steps

Pd (PPh3)4 (4.5 mg) is added to a stirred solution of 7-bromo-9-cyclopropyl-6-fluoro-9H-isothiazolo[5,4-b]quinoline-3,4-dione (23 mg, 0.065 mmole) in DMF (1 mL), followed by the addition of 2-ethynylpyridine (2 equivalents, 0.13 mmole) and diisopropyl amine (0.15 mL.) under argon at room temperature. The reaction tube is sealed and then stirred in a microwave (100 W, 90° C.) until complete as monitored by LC/MS. The reaction mixture is filtered and the filtrate concentrated in vacuo. The residue is dissolved in a mixture of DMF: CHCl3: MeOH (1:8:1) and precipitated by adding diethyl ether (1-2 ml). This process is repeated three to five times. The resulting solid, 9-cyclopropyl-6-fluoro-7-(2-(pyridin-2-yl)ethynyl) isothiazolo[5,4-b]quinoline-3,4(2H,9H)-dione, is washed with water to remove salt. The product is dried and analyzed. HPLC may be needed to obtain adequately pure product.

Provenance & Evidence