Dimethylformamide → 5-Bromo-1-methyl-1H-indole

HRID 1831852Notes

Reaction equation

HRID 1831852 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][CH:6]=[CH:5]2.[CH2:11]1N2CCN(CC2)C1.CN(C=O)C>C(OCC)(=O)C.O>[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[N:7]([CH3:11])[CH:6]=[CH:5]2

Participants

6

Reactant 3

HCID 6228DimethylformamideHCID 9237DabcoHCID 249055-Bromoindole

Product 1

HCID 2857575-Bromo-1-methyl-1H-indoleYield 989.4%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a solution of 5-bromoindole (1.0 g, 5.10 mmol) in DMC (10 mL), DABCO (0.057 g, 0.51 mmol) is added followed by DMF (1 mL). The resulting solution is heated to 90–95° C. for 5 h. The reaction is cooled to RT, and diluted with ethyl acetate (EtOAc, 50 mL) and H2O (50 mL). The organic layer is separated and washed in sequence with H2O (50 mL), 10% aqueous citric acid (2×50 mL) and H2O (4×50 mL). The organic layer is dried over anhydrous sodium sulfate (Na2SO4), filtered and concentrated under vacuum to give 5-bromo-1-methylindole (about 1.06 g, 99%) as a golden colored solid: 1H NMR (CDCl3) δ 7.72 (d, 1H), 7.26 (dd, 1H), 7.13 (d, 1H), 7.00 (d, 1H), 6.39 (d, 1H), 3.71 (s, 3H); 13C NMR (CDCl3) δ 135.3, 130.1, 129.9, 124.2, 123.2, 112.6, 110.6, 100.5, 32.9; MS m/z 209 [M+1]+.

Workup

  1. temperatureThe resulting solution is heated to 90–95° C. for 5 h
  2. customThe organic layer is separated
  3. washwashed in sequence with H2O (50 mL), 10% aqueous citric acid (2×50 mL) and H2O (4×50 mL)
  4. dry with materialThe organic layer is dried over anhydrous sodium sulfate (Na2SO4)
  5. filtrationfiltered
  6. concentrationconcentrated under vacuum

Sources & evidence

ORD record
ord-a4da9c2b870e410384e41deb19d75c36
Source dataset
uspto-grants-2006_06
Patent number
US07067676B2

Reaction notes

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