反応 #2007

反応方程式

benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate

D-Homophenylalanine benzyl ester

triethylamine

N-(t-butoxycarbonyl)-α-methylalanine

→

(R)-α-[(2-t-Butoxycarbonylamino-2-methyl-1-oxopropyl)amino]benzenebutanoic acid benzyl ester

溶媒

methylene chloride

methylene chloride

反応条件

後処理

1. 1
   workup.STIRRINGThe reaction mixture was stirred at room temperature for 2.5 h
2. 2
   その他then quenched
3. 3
   workup.ADDITIONby adding saturated brine (25 ml)
4. 4
   抽出The two phase system was extracted with methylene chloride (3×25 ml)
5. 5
   乾燥the combined methylene chloride extracts dried over magnesium sulfate powder
6. 6
   ろ過filtered
7. 7
   その他evaporated on a rotary evaporator under reduced pressure
8. 8
   その他to give a colorless oil that
9. 9
   その他on standing at room temperature
10. 10
    その他chromatographed on silica gel using an eluant
11. 11
    その他The product was isolated
12. 12
    その他after evaporation of the volatiles as a white solid

実験手順

D-Homophenylalanine benzyl ester (0.87 g; 3.23 mmol), triethylamine (900 ml) and N-(t-butoxycarbonyl)-α-methylalanine (656 mg; 3.23 mmol) were dissolved in dry methylene chloride (6.5 ml) and benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (BOP-reagent) (1.43 g; 3.23 mmol) was added with stirring in small batches over 10 minutes. The reaction mixture was stirred at room temperature for 2.5 h then quenched by adding saturated brine (25 ml). The two phase system was extracted with methylene chloride (3×25 ml) and the combined methylene chloride extracts dried over magnesium sulfate powder, filtered and evaporated on a rotary evaporator under reduced pressure to give a colorless oil that solidified to an off white solid on standing at room temperature. This solid material was taken up in the minimum volume of methylene chloride and chromatographed on silica gel using an eluant composed of ethyl acetate and hexanes in the ratio 1:3 v/v. The product was isolated after evaporation of the volatiles as a white solid. The yield of the desired product was 1.30 g (88.5%). FAB-MS: -calculated for C26H34N2O5 454.2; found 455.5 (M+1).

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