(+-)-Homocysteine → S-(2-Hydroxyethyl)homocysteine

Participants

Reaction Conditions

Reaction Steps

To D,L-homocysteine (6.69 g, 49.4 mmol) was added 2N aqueous potassium hydroxide (32 mL) and the resulting solution was cooled to 0° C. 2-Bromoethanol (4.2 mL, 59.3 mmol) in ethanol (56 mL) was then added dropwise and the reaction mixture was allowed to warm to 25° C. After 18 h the reaction mixture was acidified to pH 5 and concentrated to give 2-(amino)-4-[(2-hydroxyethyl)sulfanyl]butanoic acid (WO 9808823) as a white paste. To this material was added water (110 mL) and dioxane (110 mL) and triethylamine (20.7 mL, 148 mmol) and to the resulting solution was added 4-(2-butynyloxy)phenylsulfonyl chloride (14.2 g, 54.3 mmol). After 20 h the reaction mixture was acidified to pH 1 with 1N aqueous hydrochloric acid and extracted with dichloromethane (3×). The combined organic extracts were dried over anhydrous sodium sulfate and concentrated in vacuo to give 2-({[4-(2-butynyloxy)phenyl]sulfonyl}amino)-4-[(2-hydroxyethyl)sulfanyl]butanoic acid as an oil (20.8 g). Electrospray Mass Spec 385.8 (M−H)−.

Provenance & Evidence