Reaktion #75946

Reaktionsgleichung

carbamate

benzyl [(2R)-6-iodo-3,4-dihydro-2H-chromen-2-yl]methylcarbamate

triethylamine

t-butyl acrylate

→

product

Ausbeute 95.0%

tert-butyl (2E)-3-[(2R)-2-({[(benzyloxy)carbonyl]amino}methyl)-3,4-dihydro-2H-chromen-6-yl]-2-propenoate

Ausbeute 95.0%

Lösungsmittel

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigepreviously degassed with argon for 20 minutes
2. 2
   TemperaturThe resulting mixture was heated
3. 3
   Temperaturat gentle reflux for 26 hours
4. 4
   SonstigeThe catalyst was removed by filtration
5. 5
   EinengenThe filtrate was concentrated in vacuo
6. 6
   workup.DISSOLUTIONThe residue was dissolved in ethyl acetate (50 mL)
7. 7
   Waschenwashed with water (50 mL), brine (50 mL)
8. 8
   Trocknendried over anhydrous sodium sulfate
9. 9
   Filtrationfiltered over a pad of silica gel
10. 10
    SonstigeRemoval of solvent in vacuo

Vorschrift

Palladium acetate (224 mg, 1 mmol) was added to a mixture of the carbamate of Example 11 (4.2 g, 10 mmol), triethylamine (2.1 mL, 15 mmol), and t-butyl acrylate (1.76 mL, 12 mmol) in acetonitrile (50 mL) previously degassed with argon for 20 minutes. The resulting mixture was heated at gentle reflux for 26 hours. It was cooled to room temperature. The catalyst was removed by filtration. The filtrate was concentrated in vacuo. The residue was dissolved in ethyl acetate (50 mL), washed with water (50 mL), brine (50 mL), dried over anhydrous sodium sulfate, and filtered over a pad of silica gel. Removal of solvent in vacuo afforded the product as an oil (4.0 g, 95%): 1H NMR (CDCl3) δ1.50 (s, 9H), 1.70 1.85 (m, 1H), 200 (m, 1H), 2.80 (m, 2H), 3.40(m, 1H), 3.65 (m, 1H), 5.12 (s, 2H), 5.25 (m, 1H), 6.21 (d, J=15.3 Hz,1H), 6.76 (d, J=8.4 Hz, 1H), 7.20-7.40 (m, 7H), 7.49 (d, J=15.9 Hz, 1H); CI-MS m/z 424 (M+H+).

Quelle