Triphenylcarbinol → S-trityl-cysteine ethyl ester

Participants

Reaction Steps

To a solution of L-cysteine ethyl ester hydrochloride (18.6 g, 0.1 mole) in 200 mL TFA was added triphenylmethanol (52 g, 0.2 mole). The resulting dark brown solution was allowed to stir for 2 h at room temperature under nitrogen. The solvent was removed in vacuo and ethanol (100 mL) added to the residue. A 1 M solution of sodium ethoxide (50 mL) was added to the ethanolic solution and stirred for 90 min. during which time the solution turned cloudy. The mixture was filtered, the filtrated was concentrated in vacuo to give an oily residue. Flash column chromatography using ethyl acetate:hexane (1:3) and ethyl acetate gave the desired product (containing some ethyl acetate which is difficult to remove) which was stored under vacuum.

Provenance & Evidence