Réaction #87123

Équation de réaction

N,O-dimethylhydroxylamine HCl

(S)-2-(tert-Butoxycarbonylamino)-3-cyclopentenylpropanoic acid

ethyl chloroformate

NMM

→

(S)-tert-butyl (3-(cyclopent-1-en-1-yl)-1-(methoxy(methyl)amino)-1-oxopropan-2-yl)carbamate

Rendement 94.0%

Solvants

DCM

THF DCM

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONAfter addition
2. 2
   TempératureThe mixture was cooled to 0° C.
3. 3
   Températureto warm to ambient temperature
4. 4
   workup.STIRRINGstirred overnight
5. 5
   AutreThe mixture was quenched with water (500 mL)
6. 6
   Lavagethe organic phase was washed with water (500 mL)
7. 7
   Séchagedried over anhydrous sodium sulfate
8. 8
   Concentrationconcentrated

Mode opératoire

To a flask charged with (S)-2-(tert-Butoxycarbonylamino)-3-cyclopentenylpropanoic acid (55.0 g, 214 mmol) was added THF/DCM (800 mL, 1:1). The solution was cooled to 0° C. and ethyl chloroformate (24.5 mL, 257 mmol) and NMM (28.4 mL, 257 mmol) were added dropwise sequentially. After addition, the mixture was stirred at 0° C. under nitrogen for 1 h. To the other flask charged with N,O-dimethylhydroxylamine HCl (25 g, 257 mmol) was added DCM (400 mL). The mixture was cooled to 0° C. and TEA (38.7 mL, 278 mmol) was added. The resulting mixture was transferred into the former reaction flask. The reaction mixture was allowed to warm to ambient temperature and stirred overnight. The mixture was quenched with water (500 mL) and the organic phase was washed with water (500 mL), dried over anhydrous sodium sulfate, and concentrated to afford (S)-tert-butyl (3-(cyclopent-1-en-1-yl)-1-(methoxy(methyl)amino)-1-oxopropan-2-yl)carbamate as colorless oil (60 g, 93% yield), which was used in the next step without further purification.

Source