Hydrochloric Acid → Cyclopropyl-(7-methoxybenzofuran-2-yl)-methanone

Temperature

-78 °C

To a stirred solution of 7-methoxybenzofuran (3.0 g) in tetrahydrofuran (60 ml) cooled to -78° C. under an atmosphere of nitrogen was added dropwise n-butyllithium (1.6M in hexanes, 15.2 ml). After stirring at -78° C. for 30 minutes, magnesium bromide diethyl etherate (6.3 g) was added in single portion and the reaction mixture allowed to warm to 0° C. and stirred for 30 minutes. Cyclopropyl cyanide (1.8 ml) was then added dropwise and the mixture allowed to warm slowly to room temperature and stirred for 18 h. Aqueous hydrochloric acid (2M, 50 ml) was added to the reaction mixture and stirring continued for 1 h. The mixture was extracted with ethyl acetate (250 ml), then washed successively with water (50 ml) and brine (50 ml). The organic layer was separated and dried over magnesium sulfate, filtered and concentrated in vacuo. Purification by flash chromatography on silica eluting with 5-20% ethyl acetate in hexane afforded the title compound as a yellow oil (0.96 g).

1. temperatureto warm to 0° C.
2. stirringstirred for 30 minutes
3. temperatureto warm slowly to room temperature
4. stirringstirred for 18 h
5. stirringstirring
6. waitcontinued for 1 h
7. extractionThe mixture was extracted with ethyl acetate (250 ml)
8. washwashed successively with water (50 ml) and brine (50 ml)
9. customThe organic layer was separated
10. dry with materialdried over magnesium sulfate
11. filtrationfiltered
12. concentrationconcentrated in vacuo
13. customPurification by flash chromatography on silica eluting with 5-20% ethyl acetate in hexane

ORD record

ord-2277be75ce85420f83d2f9a29c6cdae6

Source dataset

uspto-grants-2000_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06066657