Nitrogen → 5-Benzo[b]thien-2-yl-2-hydroxy-4-methoxybenzaldehyde

Participants

Reaction Steps

Ex-62B: A stream of N2 was bubbled through a solution of 5-bromo-2-hydroxy-4-methoxybenzaldehyde (1 g, 4.3 mmol) from Ex-62A in 30 mL of ethylene glycol dimethyl ether for 15 min. Tetrakis-triphenylphosphine palladium (0) (0.5 g, 0.4 mmol) was added along with thiophene-2-boronic acid (1.2 g, 6.5 mmol) and 10 mL of Na2CO3 (2M aqueous solution). The resulting mixture was stirred under reflux overnight. The solvent was removed by rotary evaporation and the residue was treated with saturated NaHCO3 and extracted with dichloromethane. The organic phase was washed with brine, dried over MgSO4, and filtered to remove drying agent. Solvent was removed by rotary evaporation. Purification of the crude material by silica gel chromatography (hexanes/EtOAc, 2:1) gave 1.04 g of the desired 5-benzo[b]thien-2-yl-2-hydroxy-4-methoxybenzaldehyde.

Provenance & Evidence