Triethylamine → tert-Butyl 3-bromo-5-methoxy-1H-indole-1-carboxylate

A solution of 5-methoxyindole (10 g) in dry dimethylformamide (150 mL) at ambient temperature was treated with bromine (4 mL) dropwise ensuring the temperature did not rise above 30° C. The mixture was treated immediately with triethylamine (28 mL) and 4-dimethylaminopyridine (0.5 g) followed by a solution of di-tert-butyldicarbonate (18 g) in dry dimethylformamide (80 mL) and stirring was continued for a further 4 hours. The reaction mixture was evaporated and the residue was partitioned between ethyl acetate (250 mL) and water (200 mL). The aqueous layer was extracted with ethyl acetate (100 mL). The combined organic phases were washed with water (100 mL), then with brine (100 mL), then dried over magnesium sulfate and then evaporated. The residue was subjected to flash column chromatography on silica eluting with a mixture of pentane and ethyl acetate (19/1, v/v) to give the title compound (23.4 g) as a colourless solid, m.p. 111-112° C.

1. customdid not rise above 30° C
2. customThe reaction mixture was evaporated
3. customthe residue was partitioned between ethyl acetate (250 mL) and water (200 mL)
4. extractionThe aqueous layer was extracted with ethyl acetate (100 mL)
5. washThe combined organic phases were washed with water (100 mL)
6. dry with materialwith brine (100 mL), then dried over magnesium sulfate
7. customevaporated
8. additionThe residue was subjected to flash column chromatography on silica eluting with a mixture of pentane and ethyl acetate (19/1

ORD record

ord-c60f156fc64342f4bc94ab6b8ad14568

Source dataset

uspto-grants-2004_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06770643B2