5-Bromothiophene-2-carbaldehyde → 2-(5-Bromothiophen-2-yl)-1-(2-chlorophenyl)-2-hydroxyethan-1-one

Participants

Reaction Conditions

Reaction Steps

Under an atmosphere of nitrogen, to a clod (−78° C.) solution of lithium bis(trimethylsilyl)amide (8.05 mL, 1.0M solution in THF, 8.05 mmol) was added a solution of (2-chloro-phenyl)-trimethylsilanyloxy-acetonitrile (1.69 g, 7 mmol) in tetrahydrofuran (10 mL) dropwise over 10 min. After stirring for another 30 min, a solution of 5-bromothiophen-2-carboxaldehyde in tetrahydrofuran (10 mL) was added dropwise. The reaction was stirred overnight from −78° C. to reach room temperature, then was quenched by adding 3N HCl (20 mL) and warming at 40° C. for 5 hrs. After cooling, the mixture was partitioned between ethyl ether and water. The organic layer was stirred with 1M NaOH (30 mL) for 2 hrs; and the layers were separated. The organic layer was washed with brine, dried over Na2SO4, and concentrated in vacuo. The crude product was purified by chromatography on silica gel (Hexane/EtOAc, 8/2) to give a brown oil (320 mg, 14% yield). 1H-NMR (400 MHz, CDCl3): δ 4.35 (d, 1H), 6.12 (d, 1H), 7.02 (d, 1H), 7.26 (m, 2H), 7.41 (d, 1H), 7.44 (dd, 1H).

Provenance & Evidence