Dimethylformamide → 5-(5-Methylthiophen-2-yl)thiophene-2-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

Under a nitrogen atmosphere 25 mL of 2.6M solution of n-butyllithium in hexane was added to a stirred, cold (-78° C.) solution of 9.8 grams (0.058 mole) of 2,2'-bithiophene in 150 mL of tetrahydrofuran. After addition, the mixture was stirred at -78° C. for 15 minutes and then was allowed to warm to 0° C. and stirred at this temperature for one hour. Dimethyl sulfate (5.8 mL, 0.061 mole) was added, and the mixture was allowed to warm to room temperature and stir for approximately 16 hours. This mixture was cooled to -78° C., and 25 mL of 2.6M solution of n-butyllithium was added. The reaction mixture was stirred at -78° C. for fifteen minutes and was then allowed to warm to 0° C. and stirred for one hour. While maintaining a temperature of 0° C., 5.3 mL (0.068 mole) of N,N-dimethylformamide was added. After addition, the mixture was allowed to warm to room temperature and stir for two hours. The mixture was quenched with 180 mL of 10% hydrochloric acid. After stirring for 20 minutes, the organic phase was removed and diluted with diethyl ether. The aqueous phase was retained. This organic phase was washed with 10% hydrochloric acid and an aqueous solution saturated with sodium chloride. The aqueous phase from above was extracted with chloroform. This extract was washed with an aqueous solution saturated with sodium chloride and then combined with the washed organic phase. This organic mixture was dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated under reduced pressure leaving an oil. This oil was purified by column chromatography on silica gel to yield 16.0 grams of 5-formyl-5'-methyl [2,2'-bithienyl] as an oil.

Provenance & Evidence