7-Chlorothieno[3,2-b]pyridine → 2-(5-(1,3-Dioxolan-2-yl)pyridin-2-yl)-7-chlorothieno[3,2-b]pyridine

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Reaction Steps

To a solution of 7-chlorothieno[3,2-b]pyridine (14 g, 82.4 mmol) in THF (137 mL) was added, at −78° C., a solution of n-BuLi (34.4 mL, 89.3 mmol, 2.6 M in hexanes) and the reaction mixture was stirred for 10 min. A solution of ZnCl2 (89 mL, 89.3 mmol, 1.0 M in Et2O) was added and the mixture was stirred at RT for 10 min. Pd(PPh3)4 (3.18 g, 2.75 mmol) was added along with a solution of 300 (15.8 g, 68.7 mmol) in THF (50 mL) and the reaction mixture was heated to reflux under an atmosphere of N2 gas for 1 hour. The reaction mixture was then cooled to RT, and partitioned between saturated ammonium hydroxide solution and EtOAc. The organic phase was collected, dried over anhydrous Na2SO4, filtered and concentrated. The resultant material was triturated with EtOAc to afford the title compound 301 (21.4 g, 98% yield) as a beige solid. 1H NMR (300 MHz, DMSO-d6) δ (ppm): 8.71 (d, J=2.1 Hz, 1H), 8.67 (d, J=5.1 Hz, 1H), 8.49 (s, 1H), 8.36 (d, J=8.1 Hz, 1H), 8.01 (dd, J=8.1, 2.1 Hz, 1H), 7.61 (d, J=5.1 Hz, 1H), 5.91 (s, 1H), 4.16-3.96 (m, 4H).

Provenance & Evidence