Cyclopropanecarboxaldehyde → Cyclopropyl-(7-methoxybenzofuran-2-yl)-methanol

Temperature

-60 °C

To a stirred solution of 7-methoxybenzofuran (2.0 g) in tetrahydrofuran (30 ml) cooled to -60° C. under an atmosphere of nitrogen was added dropwise n-butyllithium (1.6M in hexanes, 8.9 ml). After stirring at -60° C. for 10 minutes, magnesium bromide diethyl etherate (3.8 g) was added in single portion and the reaction mixture stirred at -50° C. for 10 minutes. After cooling to -78° C., cyclopropane carboxaldehyde (1.0 ml) was added in a single portion and the mixture allowed to warm slowly to room temperature and stirred for 1 h. Water (2 ml) was added and the tetrahydrofuran removed in vacuo. The residue was partitioned between ethyl acetate (50 ml) and water (50 ml); the aqueous layer was extracted with ethyl acetate (50 ml); the organic layers were combined, dried over magnesium sulfate, filtered and concentrated in vacuo. Purification by flash chromatography on silica eluting with 0-5% methanol in dichloromethane afforded the title compound as a yellow gum (1.88 g).

1. stirringthe reaction mixture stirred at -50° C. for 10 minutes
2. temperatureAfter cooling to -78° C.
3. temperatureto warm slowly to room temperature
4. stirringstirred for 1 h
5. customthe tetrahydrofuran removed in vacuo
6. customThe residue was partitioned between ethyl acetate (50 ml) and water (50 ml)
7. extractionthe aqueous layer was extracted with ethyl acetate (50 ml)
8. dry with materialdried over magnesium sulfate
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. customPurification by flash chromatography on silica eluting with 0-5% methanol in dichloromethane

ORD record

ord-cb45695e16f24f089416f91f71eeab96

Source dataset

uspto-grants-2000_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06066657