Sodium Carbonate → HCID 14551988, compound

Participants

Reaction Conditions

Reaction Steps

In a flask are placed 2-bromo-5-chlorothiophene (0.55 mL, 5.0 mmol) and Pd(PPh3)4 (0.17 g, 0.15 mmol), and the flask is vacuum purged and nitrogen filled (3×). THF (10 mL) is added by syringe and stirred 10 min. In a separate flask is placed 5-formyl-2-thiopheneboronic acid (0.94 g, 6.0 mmol) and EtOH (2 mL) and stirred until dissolved. This mixture is added by syringe to the first flask followed by vacuum purge and nitrogen fill (3×). A solution of Na2CO3 (2M, 5.0 mL, 10.0 mmol) is added by syringe followed by vacuum purge and nitrogen fill (3×). The reaction mixture is heated at 85° C. for 20 h. The reaction is cooled to rt and diluted with water. The aqueous solution is extracted with ether (3×). The combined ether layers are washed with water (3×) then brine (2×). The ether is dried over MgSO4, filtered, and concentrated. The crude product is purified over silica gel (5% EtOAc-heptane) to provide 5′-chloro-2,2′-bithiophene-5-carboxaldehyde as an orange solid (0.27 g, 24%).

Provenance & Evidence