Triethylsilane → 4-Bromo-2,3-dihydro-1H-indole

A solution of 4-bromoindole (881 mg) in acetonitrile (18 ml) was cooled to 0° C. under argon atmosphere, and thereto were added dropwise successively triethylsilane (2.15 ml), and boron trifluoride diethyl ether complex (1.71 ml). The mixture was stirred at the same temperature for 4 hours, and then further stirred at room temperature for 1.5 hours. To the resultant mixture was added a saturated aqueous sodium hydrogen carbonate solution, and the organic solvent was evaporated under reduced pressure. The residual mixture was extracted with ethyl acetate (60 ml) twice, and the combined organic layer was dried over magnesium sulfate. The insoluble materials were filtered off, and the filtrate was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (chloroform:ethyl acetate=100:0-90:10) to give the titled compound (463 mg) as a yellow oil. APCI-Mass m/Z 198/200 (M+H). 1H-NMR (DMSO-d6) δ 2.90 (t, J=8.6 Hz, 2H), 3.45 (td, J=8.7, 1.4 Hz, 2H), 5.86 (br-s, 1H), 6.43 (d, J=7.7 Hz, 1H), 6.63 (d, J=7.9 Hz, 1H), 6.83 (t, J=7.9 Hz, 1H).

1. stirringfurther stirred at room temperature for 1.5 hours
2. customthe organic solvent was evaporated under reduced pressure
3. extractionThe residual mixture was extracted with ethyl acetate (60 ml) twice
4. dry with materialthe combined organic layer was dried over magnesium sulfate
5. filtrationThe insoluble materials were filtered off
6. customthe filtrate was evaporated under reduced pressure
7. customThe residue was purified by silica gel column chromatography (chloroform:ethyl acetate=100:0-90:10)

ORD record

ord-9423046c99cb4fffa1bdac51feb2f827

Source dataset

uspto-grants-2011_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07935674B2