Iodine → 2-Iodobenzothiophene

Temperature

0 °C

Under a nitrogen atmosphere a stirred solution of 25.0 grams (0.186 mole) of benzothiophene in 250 ml of dry tetrahydrofuran was cooled to -65° C., and 69.8 ml (0.186 mole) of n-butyllithium (2.7M in hexane) was added dropwise keeping the reaction mixture temperature below -60° C. Upon completion of addition, the reaction mixture was stirred for five minutes and then was allowed to warm to 0° C. After this time a solution of 50.8 grams (0.200 mole) of iodine in 180 ml of tetrahydrofuran was added dropwise keeping the reaction mixture temperature below 10° C. Upon completion of addition, the reaction mixture was allowed to warm to ambient temperature where it was quenched with an aqueous solution saturated with sodium metabisulfite. The reaction mixture was placed in a separatory funnel, and the organic layer was separated. The organic layer was washed with one portion of an aqueous solution saturated with sodium metabisulfite and with one portion of an aqueous solution saturated with sodium chloride. The aqueous layers were combined and washed with diethyl ether. The ether washes were combined with the organic layer, and the combination was dried with sodium sulfate. The mixture was filtered, and the filtrate was concentrated under reduced pressure to a residue. The residue was dissolved in diethyl ether and reconcentrated under reduced pressure to a residue. The residue was dissolved in warm hexane and eluted through a column of silica gel. The eluate was concentrated under reduced pressure to a volume of approximately 100 ml, and a solid crystallized from the solution. The mixture was cooled, and the solid was collected by filtration, yielding in two crops 18.9 grams of 2-iodobenzothiophene.

1. customthe reaction mixture temperature below -60° C
2. additionUpon completion of addition
3. customthe reaction mixture temperature below 10° C
4. additionUpon completion of addition
5. temperatureto warm to ambient temperature where it
6. customwas quenched with an aqueous solution saturated with sodium metabisulfite
7. customThe reaction mixture was placed in a separatory funnel
8. customthe organic layer was separated
9. washThe organic layer was washed with one portion of an aqueous solution saturated with sodium metabisulfite and with one portion of an aqueous solution saturated with sodium chloride
10. washwashed with diethyl ether
11. dry with materialthe combination was dried with sodium sulfate
12. filtrationThe mixture was filtered
13. concentrationthe filtrate was concentrated under reduced pressure to a residue
14. dissolutionThe residue was dissolved in diethyl ether
15. dissolutionThe residue was dissolved in warm hexane
16. washeluted through a column of silica gel
17. concentrationThe eluate was concentrated under reduced pressure to a volume of approximately 100 ml
18. customa solid crystallized from the solution
19. temperatureThe mixture was cooled
20. filtrationthe solid was collected by filtration

ORD record

ord-ea6d8f3ca2a149bca5d19d299b2d110f

Source dataset

uspto-grants-1991_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05073564