Triethylamine → (R)-8-Fluoro-5-methoxycarbonyl-3-(N,N-di-n-propylamino)chroman

Participants

Reaction Conditions

Reaction Steps

(R)-8-Fluoro-3-(N,N-di-n-propylamino)-5-trifloromethanesulfonyloxychroman (0.95 g, 2.4 mmol), triethylamine (0.53 g, 5.2 mmol), 1,3bis-(diphenylphosphino)propane (100 mg, catalytic amount), palladium(II)acetate (50 mg, catalytic amount) and DMF/MeOH (18 mL, 6:2) were mixed in a 50 mL three necked round bottom flask. The flask was evacuated followed by the inlet of CO (repeated three times). The reaction mixture was stirred at 70° C. for 7 hours. The solvent was removed in vacuo and the residue was dissolved in diethyl ether/2M NH3. The layers were separated and the water phase was extracted once with ether. The combined ether layers were dried (MgSO4) and the solvent was removed in vacuo to give a brown oily residue which was purified by flash chromatography (SiO2, CH2Cl2 /EtOAC, 20:1) to give 650 mg of the title compound as a clear oil (87% yield). [α]21 -92° (c 10 mg/mL MeOH). Mass spectrum (70 eV) m/z (relative intensity) 309(20, M+), 281(18), 280(100), 56(10), 43(22), 42(12), 41(16).

Provenance & Evidence