4-Chlorobenzenesulfonyl chloride → Methyl N-(4-chlorobenzene-1-sulfonyl)-L-serinate

Participants

Reaction Steps

A suspension of L-serine-methyl ester hydrochloride (5 g, 32.13 mmol) in CH2Cl2 (100 mL) was added with TEA (1.1 mol eq, 4.9 mL) and the mixture was stirred at r.t. for 10 minutes. Then 4-chlorobenzensulfonyl chloride (1 mol eq, 6.81 g) and additional TEA (1.1 mol eq) were added and the solution hated at 50° C. for 5 h. The solvent was removed under reduced pressure, water was added to the residue (100 mL) and the aqueous phase extracted with EtOAc (3×40 mL). The combined organic phases were dried over Na2SO4 and evaporated to reduced pressure. The residue was recrystallized from ethyl ether to afford 2C as white solid (8.6 g, 91% yield). 1HNMR (DMSO, 200 MHz) δ 3.51 (s, 3H), 3.60 (m, 2H), 3.91 (t, 1H), 5.17 (t, 1H), 7.50 (d, 2H, J=8), 7.89 (d, 2H, J=7.8)), 8.35 (bs, 1H).

Provenance & Evidence