Carbon Tetrachloride → Acetic acid 3-chloromethyl-benzofuran-6-yl ester

To a solution of 3-hydroxymethyl-benzofuran-6-ol (4.72 g, 28.6 mmol) in iPrOH (120 mL) was added NaOH (2.30 g, 57.5 mmol) in H2O (25 mL) followed by acetic anhydride (5.4 mL, 57.5 mmol) and the reaction mixture was stirred (rt, 1 h). The reaction was concentrated in vacuo and the resulting residue was partitioned with saturated NaHCO3 (100 mL) and EtOAc (100 mL). The layers were separated and the aqueous layer was extracted with EtOAc (3×100 mL). The organic layers were combined, dried, filtered and concentrated in vacuo. The residue was dissolved in DCM (150 mL) and treated with CCl4(3.2 mL, 32.9 mmol) and triphenylphosphine (8.64 g, 32.9 mmol) as a solution in CH2Cl2 (50 mL) and stirred (rt, 12 h). The reaction mixture was concentrated in vacuo and the resulting residue was purified by silica gel flash chromatography using DCM:hexanes (0-100%) to provide the title compound as a white solid (3.45 g, 65%). MS (ESI): mass calcd. for O11H9Cl3, 224.0; m/z found, 225.0 [M+H]+. 1H NMR (400 MHz, CDCl3): 7.68-7.64 (m, 2H), 7.28 (d, J=2.0, 1H), 7.05 (dd, J=8.5, 2.0, 1H), 4.73 (d, J=0.8, 2H), 2.33 (s, 3H).

1. concentrationThe reaction was concentrated in vacuo
2. customthe resulting residue was partitioned with saturated NaHCO3 (100 mL) and EtOAc (100 mL)
3. customThe layers were separated
4. extractionthe aqueous layer was extracted with EtOAc (3×100 mL)
5. customdried
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. dissolutionThe residue was dissolved in DCM (150 mL)
9. stirringstirred (rt, 12 h)
10. concentrationThe reaction mixture was concentrated in vacuo
11. customthe resulting residue was purified by silica gel flash chromatography

ORD-Eintrag

ord-5206c2712d6b483396c54a78259df02d

Quelldatensatz

uspto-grants-2013_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08399465B2