Reaktion #330197

Reaktionsgleichung

4-fluoro-N2-pyridin-2-yl-benzene-1,2-diamine

((S)-2-benzyloxy-1-carbamoylethyl)carbamic acid tert-butyl ester

triethyloxonium tetrafluoroborate

→

title compound

Ausbeute 53.4%

[(R)-2-Benzyloxy-1-(6-fluoro-1-pyridin-2-yl-1H-benzoimidazol-2-yl)ethyl]carbamic acid tert-butyl ester

Ausbeute 53.4%

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe volatiles were removed in vacuo
2. 2
   workup.DISSOLUTIONthe resulting residue redissolved in absolute EtOH (10 mL)
3. 3
   workup.STIRRINGthe mixture stirred at 75° C. for 16 h
4. 4
   SonstigeThe volatiles were removed in vacuo
5. 5
   Sonstigethe resulting residue partitioned between DCM
6. 6
   ExtraktionThe aqueous phase was further extracted with DCM
7. 7
   Waschenthe combined organic fractions washed with water
8. 8
   Trocknendried (MgSO4)
9. 9
   Einengenconcentrated in vacuo
10. 10
    SonstigeThe resulting residue purified by column chromatography (Si—PCC, gradient 0-30% EtOAc in cHex)

Vorschrift

To a solution of ((S)-2-benzyloxy-1-carbamoylethyl)carbamic acid tert-butyl ester (820 mg, 2.8 mmol) in anhydrous THF (10 mL) was added triethyloxonium tetrafluoroborate (550 mg, 2.9 mmol) in one portion under a nitrogen atmosphere. The resulting mixture was stirred at RT for 2 h. The volatiles were removed in vacuo and the resulting residue redissolved in absolute EtOH (10 mL). To the mixture was added 4-fluoro-N2-pyridin-2-yl-benzene-1,2-diamine (355 mg, 1.7 mmol) and the mixture stirred at 75° C. for 16 h. The volatiles were removed in vacuo and the resulting residue partitioned between DCM and a saturated aqueous solution of NaHCO3. The aqueous phase was further extracted with DCM and the combined organic fractions washed with water, dried (MgSO4) and concentrated in vacuo. The resulting residue purified by column chromatography (Si—PCC, gradient 0-30% EtOAc in cHex) to afford the title compound as a yellow oil (420 mg, 53%). LCMS (Method B): RT 3.95 min [M+H]+ 463.1.

Quelle