Ethyl Methanesulfonate → Ethyl 2-(5-chloro-2-thienyl)-2-hydroxy-1-propanesulfonate

Participants

Reaction Conditions

Reaction Steps

A solution of ethyl methanesulphonate (4.97 g) in THF (20 ml) was added dropwise to a solution of lithium hexamethyldisilylamide (42.0 ml of 1M solution in THF plus 20 ml of THF) at −78° C. under nitrogen, and the solution was stirred for 30 min. A solution of 2-acetyl-5-chlorothiophene (6.75 g) in THF (70 ml) was added to this over 15 min and the temperature maintained at −78° C. for 90 min. The reaction was quenched with saturated aqueous ammonium chloride and the mixture extracted with ethyl acetate. The combined organic fractions were washed with brine; dried (over magnesium sulphate) and concentrated under reduced pressure to afford a crude oil that was purified by Biotage™ chromatography (silica, eluting with ether-cyclohexane 1:3) to give the title compound (10.9 g) as a colourless oil.

Provenance & Evidence