Iodine → HCID 22473921, compound

A few drops of a solution of 5-bromobenzo[b]thiophene (0.93 g; prepared in a manner similar to that described in Example 21) in tetrahydrofuran (10 ml) was added under nitrogen to a mixture of magnesium turnings (0.1 g), tetrahydrofuran (2 ml) and a few small crystals of iodine, heat was applied to initiate the reaction, then the remainder of the bromobenzo[b]thiophene solution was added at reflux temperature over 10 minutes. When the addition was complete, the mixture was heated under reflux for 45 minutes, then a solution of N-methoxy-N-methylbutyramide (0.6 g) in tetrahydrofuran (10 ml) was added. The mixture was heated under reflux for 1 hour, cooled to ambient temperature, then quenched by the addition of 2M hydrochloric acid (15 ml). Ethyl acetate (25 ml) was added, the mixture was stirred at ambient temperature for 45 minutes, the organic layer was separated, then further product was isolated from the aqueous layer by extraction into ethyl acetate (20 ml). The combined ethyl acetate solutions were washed with water (2×10 ml) and saturated aqueous sodium chloride solution (10 ml), then they were dried (MgSO4) and the solvents were removed in vacuo. The residue was purified by flash chromatography over silica using petroleum ether (b.p. 60-80° C.) followed by a 95:5 mixture of petroleum ether (b.p. 60-80° C.) and ethyl acetate as eluants. Appropriate fractions were combined and the solvents removed in vacuo to give 1-(benzo[b]thiophen-5-yl)butan-1-one (0.1 g) as a yellow oil which was used without further purification.

1. customprepared in a manner similar to
2. customthe reaction
3. temperatureat reflux temperature over 10 minutes
4. additionWhen the addition
5. temperaturethe mixture was heated
6. temperatureunder reflux for 45 minutes
7. temperatureThe mixture was heated
8. temperatureunder reflux for 1 hour
9. customquenched by the addition of 2M hydrochloric acid (15 ml)
10. additionEthyl acetate (25 ml) was added
11. customthe organic layer was separated
12. customfurther product was isolated from the aqueous layer by extraction into ethyl acetate (20 ml)
13. washThe combined ethyl acetate solutions were washed with water (2×10 ml) and saturated aqueous sodium chloride solution (10 ml)
14. dry with materialthey were dried (MgSO4)
15. customthe solvents were removed in vacuo
16. customThe residue was purified by flash chromatography over silica
17. additionfollowed by a 95:5 mixture of petroleum ether (b.p. 60-80° C.) and ethyl acetate as eluants
18. customthe solvents removed in vacuo

ORD record

ord-b45cbc51677947e69d13b65a69111075

Source dataset

uspto-grants-2005_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06900216B2