Reaction #838933

Reaction equation

N-Boc-N-methyl-L-alanine

N-methylmorpholine

L-alanine benzyl ester hydrochloride

HOBt

EDC

→

Benzyl (S)-2-[(S)-2-(tert-butoxycarbonyl-methyl-amino)-propanoylamino]-propionate

Solvents

toluene

water

dimethylformamide

Conditions

Workup

1. 1
   Extractionextracted
2. 2
   workup.STIRRINGwith shaking
3. 3
   ExtractionThe aqueous phase is extracted twice with toluene
4. 4
   Dryingthe combined organic phases are dried over sodium sulfate
5. 5
   Concentrationconcentrated to dryness
6. 6
   Filtrationafter filtration
7. 7
   OtherThe product is purified chromatographically by silica gel chromatography on about 1500 ml of silica gel
8. 8
   Other7.9 g (97% of th.) of the product are obtained

Procedure

4.81 g (22.3 mmol) of L-alanine benzyl ester hydrochloride, 3.32 g (24.6 mmol) of HOBt and 4.92 g (25.7 mmol) of EDC are introduced into 10 ml of anhydrous dimethylformamide under argon. At 0° C., 4.54 g (22.3 mmol) of N-Boc-N-methyl-L-alanine and 14.7 ml (133.9 mmol) of N-methylmorpholine are added, and the reaction mixture is stirred overnight with slow warming to RT. The reaction solution is treated with water and toluene and extracted with shaking. The aqueous phase is extracted twice with toluene, and the combined organic phases are dried over sodium sulfate and concentrated to dryness after filtration. The product is purified chromatographically by silica gel chromatography on about 1500 ml of silica gel using MeOH/dichloromethane 10/1. 7.9 g (97% of th.) of the product are obtained.

Source