反応 #453371

反応方程式

Citric acid

iodomethane

(2R)-3-Benzyloxy-2-tert-butoxycarbonylaminopropionic acid

tetrahydrofuran

sodium hydride

→

(2R)-3-benzyloxy-2-(tert-butoxycarbonylmethylamino)propionic acid

反応条件

後処理

1. 1
   その他Tetrahydrofuran was removed in vacuo
2. 2
   抽出the residue was extracted with methylene chloride (3×100 mL)
3. 3
   乾燥The organic phase was dried (magnesium sulfate)
4. 4
   その他evaporated in vacuo
5. 5
   workup.DISSOLUTIONThe residue was dissolved in diethyl ether (20 mL)
6. 6
   workup.ADDITIONdicyclohexylamine (10 mL) and heptane (100 mL) were added
7. 7
   workup.WAITThe reaction mixture was left 3 days
8. 8
   workup.STIRRINGwithout stirring at 0° C
9. 9
   ろ過The reaction mixture was filtered

実験手順

(2R)-3-Benzyloxy-2-tert-butoxycarbonylaminopropionic acid (7.0 g; 23.7 mmol) was dissolved in dry tetrahydrofuran and iodomethane (11.9 mL; 189 mmol) was added. The reaction mixture was cooled to 0° C. and sodium hydride (60% in mineral oil) (2.73 g; 71 mmol) was added. The reaction mixture was left 3 days without stirring at 0° C. Citric acid (5%) was added until pH 2.5. Tetrahydrofuran was removed in vacuo and the residue was extracted with methylene chloride (3×100 mL). The organic phase was dried (magnesium sulfate) and evaporated in vacuo. The residue was dissolved in diethyl ether (20 mL) and dicyclohexylamine (10 mL) and heptane (100 mL) were added. The reaction mixture was left 3 days without stirring at 0° C. The reaction mixture was filtered to afford 5.78 g of (2R)-3-benzyloxy-2-(tert-butoxycarbonylmethylamino)propionic acid.

出典