Sodium Carbonate → 5-Chloro-2,2'-bithiophene

Participants

Reaction Steps

To a solution of 2-bromo-5-chlorothiophene (4.11 g), thiophene-2-boronic acid (4.00 g), tetrakis(triphenylphosphine)palladium (0) (1.20 g) and 2M aqueous sodium carbonate solution (31.3 ml) in dimethoxyethane (100 ml) was heated under reflux under argon atmosphere for 2.5 hours. The reaction mixture was cooled, and extracted with ethyl acetate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (hexane) to give 2-(5-chloro-2-thienyl)thiophene (3.37 g) as pale yellow oil. (2) The above 2-(5-chloro-2-thienyl)thiophene and 5-bromo-2-methylbenzoic acid obtained in Reference Example 4-(1) were used and treated in a manner similar to Reference Example 5 to give 5-bromo-1-(5-(5-chloro-2-thienyl)-2-thienylmethyl)-2-methylbenzene as a colorless solid. APCI-Mass m/Z 383/385 (M+H).

Provenance & Evidence