反应详情

温度

-78 °C

A 100 mL round bottomed flask equipped with magnetic stir bar was charged with 1.7 g benzyl 3-chlorosulfonyl-2(R)-methylpropionate from Example 3 in 25 mL CH2Cl2. The solution was cooled to −78° C. and 15 mL of anhydrous dimethylamine was slowly added. After 30 minutes the reaction was concentrated in vacuo and the residue was partioned between EA/H2O. The organic phase was dried, concentrated in vacuo to yield 1.4 g of benzyl 3-[(dimethylamino)sulfonyl]-2(R)-methylpropionate as a clear amber oil which was used directly in the next step. Part B: 3-[(dimethylamino)sulfonyl]-2(R)-methylpropionic acid A 100 mL Fisher/Porter vessel was charged with 1.4 g of benzyl 3-[(dimethylamino)sulfonyl]-2(R)-methylpropionate in 30 mL acetic acid with a catalytic amount of 10% Pd—C. The reaction was hydrogenated at 50 psi for 24 hours, filtered through Celite and concentrated in vacuo. The residue was azeotroped with toluene then concentrated in vacuo to afford 900 mg of 3-[(dimethylamino)sulfonyl]-2(R)-methylpropionic acid which was used without further purification.

1. customA 100 mL round bottomed flask equipped with magnetic stir bar
2. concentrationAfter 30 minutes the reaction was concentrated in vacuo
3. customThe organic phase was dried
4. concentrationconcentrated in vacuo