Methyl iodide → N-Methylcarbazole

HRID 1749239Notes

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.[H-].[Na+].I[CH3:17]>CN(C=O)C>[CH3:17][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

Conditions

Temperature: 80 °C

Procedure

To a solution of carbazole (3.34 g, 20 mmol) in DMF (80 mL) at 0° C. was added NaH (0.72 g, 30 mmol). After heating at 80° C. for 1.5 h, iodomethane (3.4 g, 24 mmol) was added dropwise. The resulting mixture was kept at 80° C. overnight. After cooling down to 0° C., the reaction mixture was carefully quenched with water and extracted with ethyl acetate three times. The combined organic phase was washed with water and brine. Then the organic layer was dried over anhydrous sodium sulfate and the solvent was removed. The residue was purified by silica gel chromatography using petroleum ether and ethyl acetate as eluent (EA:PE=1:5) to afford methylated carbazole 1b (2.78 g) as yellow oil in 77% yield. 1H NMR (400 MHz, CDCl3) δ 8.08 (d, J=8.0 Hz, 2H), 7.46 (t, J=8.0 Hz, 2H), 7.36 (d, J=8.0 Hz, 2H), 7.22 (t, J=8.0 Hz, 2H), 3.79 (s, 3H). 13C NMR (400 MHz, CDCl3) δ 140.9, 125.6, 122.7, 120.2, 118.8, 108.4, 28.9.

Workup

temperatureAfter cooling down to 0° C.
customthe reaction mixture was carefully quenched with water
extractionextracted with ethyl acetate three times
washThe combined organic phase was washed with water and brine
dry with materialThen the organic layer was dried over anhydrous sodium sulfate
customthe solvent was removed
customThe residue was purified by silica gel chromatography

Sources & evidence

ORD record: ord-673c19cc351d408486bb3dc2569d9dde
Source dataset: uspto-grants-2015_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09156814B2

Reaction notes

Loading…