Reaktion #160059

Reaktionsgleichung

9-(tert-butoxycarbonyl)-4-(2,2-difluoroethyl)-1-oxa-4,9-diazaspiro[5.5]undecane-2-carboxylic acid

prop-2-en-1-amine

T3P

triethylamine

→

tert-butyl 2-(allylcarbamoyl)-4-(2,2-difluoroethyl)-1-oxa-4,9-diazaspiro[5.5]undecane-9-carboxylate

Ausbeute 83.2%

Lösungsmittel

2-methyltetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe reaction mixture was then quenched with saturated NaHCO3 solution (3 mL)
2. 2
   workup.STIRRINGstirred for an additional 10 minutes
3. 3
   workup.ADDITIONdiluted with EtOAc
4. 4
   Sonstigethe layers were separated
5. 5
   ExtraktionThe aqueous layer was extracted once more with EtOAc
6. 6
   Trocknenthe combined organics were dried over Na2SO4
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated in vacuo to an oil
9. 9
   SonstigeThe residue was purified by silica gel column chromatography

Vorschrift

To 9-(tert-butoxycarbonyl)-4-(2,2-difluoroethyl)-1-oxa-4,9-diazaspiro[5.5]undecane-2-carboxylic acid (520 mg, 1.43 mmol), prop-2-en-1-amine (118 μL, 1.57 mmol) and T3P (2.12 mL of 50% w/w, 3.59 mmol) in 2-methyltetrahydrofuran (4 mL) was added triethylamine (597 μL, 4.28 mmol) at room temperature and the reaction mixture was stirred for 2 hours. The reaction mixture was then quenched with saturated NaHCO3 solution (3 mL) and stirred for an additional 10 minutes, then diluted with EtOAc and the layers were separated. The aqueous layer was extracted once more with EtOAc, and the combined organics were dried over Na2SO4, filtered and concentrated in vacuo to an oil. The residue was purified by silica gel column chromatography using 0-50% EtOAc in hexanes to yield tert-butyl 2-(allylcarbamoyl)-4-(2,2-difluoroethyl)-1-oxa-4,9-diazaspiro[5.5]undecane-9-carboxylate (480 mg, 83%). ESI-MS m/z calc. 403.2. Found 404.5 (M+1)+; Retention time: 1.78 minutes (3 min run).

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