Indole → 3-(1,1-Dimethylethyl)-1H-indole

To a mixture of indole (5 g, 42.7 mmol), zinc triflate (9.3 g, 25.6 mmol), and tetrabutylammonium iodide (7.9 g, 21.4 mmol) in anhydrous toluene (120 mL) was added diisopropylethylamine (8.2 mL, 47 mmol) at room temperature under a blanket of nitrogen. After the reaction was stirred 15 minutes at room temperature, the reaction mixture was treated with tert-butyl bromide (2.5 mL, 21.7 mmol). The reaction solution was stirred at room temperature under nitrogen for 3 hours, then poured into a saturated aqueous solution of ammonium chloride (150 mL). The organic layer was separated and the aqueous layer was extracted with ethyl acetate (3×50 mL). The combined organic layers were dried over magnesium sulfate, concentrated, and the residue was purified via flash column chromatography (silica, 10% ethyl acetate in hexane) to afford 3-tert-butyl-1H-indole as a white solid. MS (ES) m/z 174.2.

1. stirringThe reaction solution was stirred at room temperature under nitrogen for 3 hours
2. customThe organic layer was separated
3. extractionthe aqueous layer was extracted with ethyl acetate (3×50 mL)
4. dry with materialThe combined organic layers were dried over magnesium sulfate
5. concentrationconcentrated
6. customthe residue was purified via flash column chromatography (silica, 10% ethyl acetate in hexane)

ORD record

ord-037fa52706c448ae87b4f2c0eda40c35

Source dataset

uspto-grants-2009_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07517899B2