Hydrochloric Acid → 3-(5-Chloro-thiophen-2-yl)-3-oxo-propionic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A 0.25M THF solution of tert-butyl acetate (2.90 g, 25 mmol) is added dropwise to a cold (−78° C.) solution of potassium bis(trimethylsilyl)amide (100 ml of a 0.5M toluene solution) and ethyl 5-chlorothiophene-2-carboxylate (Lancaster)(4.77 g, 25 mmol) in 50 ml of THF. The reaction is allowed to warm to 0° C. over one hour. After stirring an additional hour at 0° C., the reaction is poured into 100 ml of a 1M HCl solution. The organic layer is extracted with brine and evaporated in vacuo. The crude residue is purified by flash column chromatography eluting with 5% ethyl acetate/hexane to provide the product (4.54 g, 17 mmol) as an oil. 1H NMR (CDCl3, 300 MHz) δ7,53 (d, 1H), 6.98 (d, 1H), 3.78 (3, 2H), 1.50 (s, 9H).

Provenance & Evidence