Lithium Hydroxide → 3-[4-(2-(4-benzylsulfonylaminophenyl)ethoxy}phenyl]-2-(S)-ethoxypropanoic acid

Participants

Reaction Steps

3-[4-{2-(4-Benzylsulfonylaminophenyl)ethoxy}phenyl]-2-(S)-ethoxypropanoic acid ethyl ester (described in Example 66) (0.15 g; 0.29 mmole) was dissolved in tetrahydrofuran(2 ml). Lithium hydroxide (0.0084 g; 0.35 mmole) in water (2 ml) was added. The reaction mixture was stirred at room temperature. After 6 hours, the reaction was checked by TLC (silica gel, ethyl acetate:heptane=50:50) and it was not complete. More. lithium hydroxide (approx. 0.01 g), was added the reaction mixture was stirred overnight and tetrahydrofuran was evaporated. The remaining solution was extracted with diethyl ether. The water phase was acidified with hydorchloric acid (1%) to pH˜2 and extracted twice with ethyl acetate. The organic phases were combined, dried with magnesium sulfate and the solvent was evaporated. Chromatography of the residue on silica gel (Isolute, SI) using dichloromethane and then dichloromethane:methanol (98:2) as eluant gave 0.125 g (88% yield) of 3-[4-{2-(4-benzylsulfonylaminophenyl)ethoxy}phenyl]-2-(S)-ethoxypropanoic acid.

Provenance & Evidence