Reaktion #70822

ord-9b74e036973a41e4be89156d2b6cabaf

Reaktionsbedingungen

Temperatur
-78°CELSIUS
Detaillierte Bedingungen
See reaction.notes.procedure_details.

Aufarbeitung

  1. 1
    workup.ADDITIONUpon completion of addition
  2. 2
    workup.STIRRINGUpon completion of the transfer, the reaction was stirred for 45 minutes
  3. 3
    Sonstigequenched with saturated ammonium chloride solution
  4. 4
    Sonstigeto come to room temperature
  5. 5
    Sonstigethe aqueous and organic layers were separated
  6. 6
    ExtraktionThe aqueous phase was extracted 3× with ethyl acetate
  7. 7
    Waschenthe combined organic phases were washed with brine
  8. 8
    Trocknendried over sodium sulfate
  9. 9
    Einengenconcentrated in vacuo
  10. 10
    Sonstigeto yield a residue
  11. 11
    SonstigeThe residue was purified over silica gel
  12. 12
    Wascheneluting with 1%

Vorschrift

In a flame-dried three-neck flask, a solution of 2-(benzyloxymethyl)-2H-tetrazole (2.01 g, 10.57 mmol) and tetramethylethylenediamine (3.16 mL, 21.4 mmol) in diethyl ether (30 mL) was cooled to −78° C. Once at the prescribed temperature, the mixture was treated with the dropwise addition of n-butyllithium (1.6 M in hexanes, 7.3 mL, 11.62 mmol), which caused the color of the solution to turn dark red. Upon completion of addition, the mixture was stirred for 10 minutes, and then transferred via cannula to a solution of tributyltin chloride (2.9 mL, 10.57 mmol) in diethyl ether (20 mL) which had been pre-cooled to −78° C. Upon completion of the transfer, the reaction was stirred for 45 minutes, and then quenched with saturated ammonium chloride solution. The mixture was allowed to come to room temperature, and the aqueous and organic layers were separated. The aqueous phase was extracted 3× with ethyl acetate, and the combined organic phases were washed with brine, dried over sodium sulfate, and concentrated in vacuo to yield a residue. The residue was purified over silica gel, eluting with 1% then 5% then 10% ethyl acetate/hexanes to yield 2-(benzyloxymethyl)-5-(tributylstannyl)-2H-tetrazole (3.0 g, 60% yield) as a colorless oil.

Quelle

DOI: 10.6084/m9.figshare.5104873.v1Patent: US08536198B2uspto-grants-2013_09