Reaktion #557388

Reaktionsgleichung

diisopropylamine

n-butyl lithium

tert-butyl N-allyl-N-[2-(methoxy(methyl)amino)-2-oxo-ethyl]carbamate

isothiazole

ammonium chloride

→

title compound

Ausbeute 86.3%

tert-Butyl N-allyl-N-(2-isothiazol-5-yl-2-oxo-ethyl)carbamate

Ausbeute 86.3%

Lösungsmittel

—

hexanes

ethyl acetate

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe resultant white slurry is stirred for 30 minutes at −78° C
2. 2
   workup.STIRRINGThe reaction is then stirred for 30 minutes at −78° C.
3. 3
   Temperaturwarmed to ambient temperature
4. 4
   workup.STIRRINGis stirred for 30 minutes
5. 5
   ExtraktionThe resulting solution is extracted three times with ethyl acetate
6. 6
   TrocknenThe combined organic layers are dried over sodium sulfate
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated under vacuum
9. 9
   SonstigeThe crude product is purified over silica gel with a 35 minute

Vorschrift

To a −78° C. solution of diisopropylamine (9.01 mL, 64.01 mmol) in tetrahydrofuran (80 mL) is added n-butyl lithium (30.78 mL, 49.24 mmol, 1.6 M in hexanes) drop wise under nitrogen. The resulting solution is stirred at −78° C. for 20 minutes and then a solution of isothiazole (4.19 g, 49.24 mmol) in tetrahydrofuran (10 mL) is added drop wise. The resultant white slurry is stirred for 30 minutes at −78° C. A solution of tert-butyl N-allyl-N-[2-(methoxy(methyl)amino)-2-oxo-ethyl]carbamate (6.36 g, 24.62 mmol) in tetrahydrofuran (50 mL) is then added to the slurry over a 15 minutes period. The reaction is then stirred for 30 minutes at −78° C., warmed to ambient temperature and is stirred for 30 minutes. Saturated ammonium chloride (200 mL) is then added. The resulting solution is extracted three times with ethyl acetate. The combined organic layers are dried over sodium sulfate, filtered, and concentrated under vacuum. The crude product is purified over silica gel with a 35 minute, 5% to 100% ethyl acetate in hexanes gradient, to give the title compound (6.00 g, 21.25 mmol, 86%). ES/MS (m/e): 283.0 (M+H).

Quelle