Triethylamine → 7-Methyl-9-(3-(phenyl)propoxy)-5H-furo[3,2-g]chromen-5-one

Participants

Reaction Conditions

Reaction Steps

9-(3-Phenylpropoxy)-7-methyl-4-trifluoromethanesulfonyl-5H-furo[3,2-g]chromen-5-one (1.5 g, 3.11 mmol, 0.2M, prepared from the corresponding 4-hydroxy system according to General Procedure G, Step 1) was dissolved in anhydrous dimethylformamide and treated with triethylammonium formate (1.8 g, 12.4 mmol.). The reaction flask was evacuated and back-filled with N2 three times. Anhydrous triethylamine (0.63 g, 6.20 mmol), Pd(OAc)2 (70 mg, 0.31 mmol) and triphenylphosphine (0.16 mg, 0.62 mmol) were added to the reaction mixture and the flask was again evacuated and back-filled with N2. The reaction mixture was heated to 60-70° C. for 24 hours under a N2 atmosphere. The solvents were removed under vacuum and the residue was dissolved in ethyl acetate and washed with saturated aqueous NH4Cl solution. The organic layer was dried over MgSO4, concentrated under vacuum and the crude residue was purified by silica gel chromatography, eluting with diethyl ether:dichloromethane (0:1, then 1:3) to afford the title compound as a pale yellow solid (75%). 1H NMR (300 MHz, CDCl3) δ: 2.06-2.16 (m, 2H), 2.41 (s, 3H, CH3), 2.92 (t, J=7.5 Hz, 2H), 4.49 (t, J=6.6 Hz, 2H), 6.15 (s, 1H), 6.85 (d, J=2.1 Hz, 1H), 7.16-7.30 (m, 5H), 7.69 (d, J=2.1 Hz, 1H), 8.09 (s, 1H). MS (ES+) m/z: 335 (M+H+).

Provenance & Evidence