Hydrochloric Acid → 6-Bromo-2,3,4,9-tetrahydro-1H-carbazol-1-one

HRID 877511Notes

Reaction equation

Cl.[Br:2][C:3]1[CH:8]=[CH:7][C:6]([NH:9]N)=[CH:5][CH:4]=1.[C:11]1(=O)[CH2:16][CH2:15][CH2:14][CH2:13][C:12]1=[O:17].Cl>CO.CC(O)=O>[Br:2][C:3]1[CH:8]=[C:7]2[C:6](=[CH:5][CH:4]=1)[NH:9][C:11]1[C:12](=[O:17])[CH2:13][CH2:14][CH2:15][C:16]2=1

Participants

Conditions

Temperature: 60 °C

Procedure

4-Bromophenyl hydrazine hydrochloride (0.3 g, 1.3 mmol) in MeOH (3 mL) was heated to 60° C. and 1,2-cyclohexanedione (0.16 g, 1.4 mmol), dissolved in AcOH (4 mL) and conc. HCl (1.5 mL) were added while maintaining the temperature at 60° C. After the addition was completed, the reaction mixture was cooled to room temperature and stirred for 12 h during time a solid precipitated out. The mixture was basified with aq NaHCO3 and extracted with EtOAc (3×25 mL). The combined organic extracts were washed with water, dried over Na2SO4 and concentrated in vacuo to give the crude product which was purified by column chromatography to give the title compound as a pale yellow solid (0.080 g, 22%). 1H NMR (500 MHz, CDCl3, δ in ppm) 8.8 (bs, 1H), 7.8 (s, 1H), 7.43 (dd, J=10.0, 2.0 Hz, 1H), 7.24 (d, J=9.5 Hz, 1H), 2.98 (t, J=8.0 Hz, 2H), 2.63 (t, 8.0 Hz, 2H), 2.24 (m, 2H).

Workup

additionAfter the addition
temperaturethe reaction mixture was cooled to room temperature
customprecipitated out
extractionextracted with EtOAc (3×25 mL)
washThe combined organic extracts were washed with water
dry with materialdried over Na2SO4
concentrationconcentrated in vacuo
customto give the crude product which
customwas purified by column chromatography

Sources & evidence

ORD record: ord-b7008891aa4e4f1ab9d084c886c9673f
Source dataset: uspto-grants-2015_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08987319B2

Reaction notes

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