Reaktion #48398

Reaktionsgleichung

iodine

benzyl (2R,5E)-2-[bis(tert-butoxycarbonyl)amino]-6-nitrohex-5-enoate

1-bromo-2,3-dichlorobenzene

magnesium

→

title compound

Ausbeute 176.3%

(3R)-3-Amino-6-(2,3-dichlorophenyl)azepan-2-one

Ausbeute 176.3%

Lösungsmittel

diethyl ether

diethyl ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThis mixture was refluxed for 3 h
2. 2
   Sonstige2.0 mL of the Grignard solution prepared
3. 3
   workup.ADDITIONabove was added
4. 4
   workup.ADDITIONAfter 1 and 2 h, respectively, 2.0 and 1.0 mL of the Grignard solution was added
5. 5
   SonstigeThe reaction was quenched with a saturated aqueous solution of ammonium chloride
6. 6
   Sonstigethe phases separated
7. 7
   Waschenthe organic phase washed with saturated aqueous sodium potassium tartrate and brine
8. 8
   TrocknenThe combined organics were dried over magnesium sulfate
9. 9
   Filtrationfiltered
10. 10
    Einengenconcentrated
11. 11
    Sonstigeto give a residue that
12. 12
    Sonstigewas purified by silica gel chromatography (0%→3% methanol/dichloromethane)

Vorschrift

To a slurry of 1-bromo-2,3-dichlorobenzene (1.46 g, 6.46 mmol) in diethyl ether (10 mL) was added magnesium (0.157 g, 6.46 mmol) and a crystal of iodine. This mixture was refluxed for 3 h, and then cooled to room temperature. A solution of benzyl (2R,5E)-2-[bis(tert-butoxycarbonyl)amino]-6-nitrohex-5-enoate (0.50 g, 1.08 mmol) in diethyl ether (10 mL) was cooled to 0° C., and 2.0 mL of the Grignard solution prepared above was added. After 1 and 2 h, respectively, 2.0 and 1.0 mL of the Grignard solution was added. The reaction was quenched with a saturated aqueous solution of ammonium chloride, the phases separated and the organic phase washed with saturated aqueous sodium potassium tartrate and brine. The combined organics were dried over magnesium sulfate, filtered and concentrated to give a residue that was purified by silica gel chromatography (0%→3% methanol/dichloromethane) to give the title compound (0.52 g). MS 411.0 (M+1-2Boc).

Quelle