Methanesulfonyl chloride → Ethyl 2-(methylsulfonyloxy)-2-(thiophen-2-yl)acetate

Participants

Reaction Conditions

Reaction Steps

Hydroxy-thiophen-2-yl-acetic acid ethyl ester (4.58 g, 24.6 mmol) is dissolved in dry DCM (125 mL) and cooled at 0° C. DIPEA (5.15 mL, 29.5 mmol) and methanesulphonyl chloride (2.11 mL, 27.1 mmol) are added and the resulting solution is stirred at RT for 1 hour. DIPEA (0.859 ml, 4.92 mmol) and methanesulphonyl chloride (0.19 mL, 2.46 mmol) are added again. After being stirred at room temperature for 1 additional hour, a third portion of DIPEA (0.43 mL, 2.46 mmol) and methanesulphonyl chloride (77 ul, 0.98 mmol) is added. After 1 hour the reaction is completed. The mixture is diluted with DCM, washed with sat. NaHCO3, water and brine, dried (Na2SO4), filtered and evaporated. The resulting yellow oil is used in the next step without any further purification.

Provenance & Evidence