Carbazole → N-Methylcarbazole

HRID 488537Notes

Reaction equation

HRID 488537 reaction equation
[CH:1]1[C:13]2[NH:12][C:11]3[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=3)[C:5]=2[CH:4]=[CH:3][CH:2]=1.[CH2:14]1N2CCN(CC2)C1>CCOC(C)=O.O>[CH3:14][N:12]1[C:11]2[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=2[C:5]2[C:13]1=[CH:1][CH:2]=[CH:3][CH:4]=2

Participants

5

Reactant 2

HCID 6854CarbazoleHCID 9237Dabco

Product 1

HCID 15142N-MethylcarbazoleYield 961.2%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
92.5 °C

Procedure

To a solution of carbazole (1.03 g, 6.16 mmol) in DMC (10 mL), DABCO (0.069 g, 0.62 mmol) is added and the resulting solution is heated to 90-95° C. for 24 h. The reaction is cooled to RT, and diluted with EtOAc (40 mL) and H2O (40 mL). The organic layer is separated and washed in sequence with H2O (50 mL), 10% aqueous citric acid (2×40 mL) and H2O (3×40 mL). The organic layer is dried over anhydrous Na2SO4, filtered and concentrated under vacuum to give 9-methylcarbazole (about 1.08 g, 97%) as a beige solid: 1H NMR (CDCl3) δ8.06 (d, 2H), 7.43 (t, 2H), 7.31 (d, 2H), 7.20 (t, 2H), 3.71 (s, 3H); 13C NMR (CDCl3) δ141.0, 125.7, 122.8, 120.3, 118.9, 108.5, 29.0; MS m/z 181 [M+1]+.

Workup

  1. temperatureThe reaction is cooled to RT
  2. customThe organic layer is separated
  3. washwashed in sequence with H2O (50 mL), 10% aqueous citric acid (2×40 mL) and H2O (3×40 mL)
  4. dry with materialThe organic layer is dried over anhydrous Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated under vacuum

Sources & evidence

ORD record
ord-96f89865451a4c6e823a791e47639282
Source dataset
uspto-grants-2005_12
Patent number
US06972336B2

Reaction notes

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