2,6-Lutidine → 6-Hydroxy-2-methyl-2,3-dihydro-benzofuran-4-carboxylic acid methyl ester

Temperature

0 °C

2,6-Lutidine (2.64 mL, 22.7 mmol) and BBr3 (22.7 mL, 22.7 mmol, 1.0 M solution in CH2Cl2) were added to a mixture of 4-methoxy-2-methyl-2,3-dihydro-benzofuran-6-carboxylic acid methyl ester and 6-methoxy-2-methyl-2,3-dihydro-benzofuran-4-carboxylic acid methyl ester (1d) (1.68 g, 7.58 mmol) in CH2Cl2 (30 mL) at 0° C. The mixture was stirred at 0° C. and the warmed to room temperature overnight. The mixture was quenched with H2O (80 mL) and extracted with CH2Cl2 (2×80 mL). The organic layers were dried over MgSO4 and concentrated. The residue was purified by flash column chromatography eluting with 20-30% EtOAc in hexanes to give a pale brown colored solid (366 mg, 23% yield). 1H NMR (400 MHz, CDCl3) δ 6.99 (d, J=2.27 Hz, 1 H) 6.49 (d, J=2.27 Hz, 1 H) 5.46 (s, 1 H) 4.86-5.07 (m, 1 H) 3.89 (s, 3 H) 3.57 (dd, J=16.93, 8.84 Hz, 1H) 3.03 (dd, J=16.93, 7.33 Hz, 1 H) 1.46 (d, J=6.32 Hz, 3 H); LCMS for C11H12O4 m/z 209.0 (M+H)+.

1. temperaturethe warmed to room temperature overnight
2. customThe mixture was quenched with H2O (80 mL)
3. extractionextracted with CH2Cl2 (2×80 mL)
4. dry with materialThe organic layers were dried over MgSO4
5. concentrationconcentrated
6. customThe residue was purified by flash column chromatography
7. washeluting with 20-30% EtOAc in hexanes

ORD record

ord-976dcfbd14fc4622a8b99a9656960c37

Source dataset

uspto-grants-2012_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08119624B2