Réaction #80549

Équation de réaction

(R)-3-(N,N-Dicyclobutylamino)-8-fluoro-5-trifluoromethylsulfonyloxy-3,4-dihydro-2H-1-benzopyran

DMF methanol

carbonmonoxide

triethylamine

→

title compound

Rendement 78.0%

Methyl (R)-3-(N,N-Dicyclobutylamino)-8-fluoro-3,4-dihydro-2H-1-benzopyran-5-carboxylate

Rendement 78.0%

Conditions de réaction

Traitement

1. 1
   Autredegassed
2. 2
   Autrethe reaction mixture was degassed
3. 3
   Températureto cool
4. 4
   Autrethe solvent was removed in vacuo
5. 5
   Extractionextracted
6. 6
   SéchageThe combined ether portions were dried (MgSO4)
7. 7
   Filtrationfiltered
8. 8
   Autrethe solvent removed in vacuo
9. 9
   Autreto give the crude residue

Mode opératoire

(R)-3-(N,N-Dicyclobutylamino)-8-fluoro-5-trifluoromethylsulfonyloxy-3,4-dihydro-2H-1-benzopyran (0.82 g, 1.94 mmol) was dissolved in a solution of DMF/methanol (6:2, 15 mL) and then degassed followed by the inlet of carbonmonoxide (×3). With a slight positive pressure of carbonmonoxide, palladium(II)-acetate (14 mg), 1,3-bis(diphenylphosphino)propane (25 mg) and triethylamine (0.60 mL, 4.3 mmol) were added and the reaction mixture was degassed and subjected to carbonmonoxide once again. The reaction was heated to 70° C. under carbornmonoxide atmosphere with vigorous stirring for 5.5 h. The reaction was allowed to cool and the solvent was removed in vacuo. The remains were taken into a 2M solution of NH3 and then extracted, twice, with diethyl ether. The combined ether portions were dried (MgSO4), filtered, and the solvent removed in vacuo to give the crude residue. Chromatography on silica (eluent: 12.5% ethyl acetate/hexane) gave 501 mg (78% yield) of the title compound as a clear oil. [α]21D =-138.2° (C=0.1; CHCl3) GC-MS (70 eV) M=333 (4%).

Source