Phosphorus oxychloride → ethyl 5-bromo-8-cyano-9H-carbazole-2-carboxylate

HRID 1811095Notes

Reaction equation

[Br:1][C:2]1[CH:14]=[CH:13][C:12]([C:15](=O)[NH2:16])=[C:11]2[C:3]=1[C:4]1[CH:5]=[CH:6][C:7]([C:18]([O:20][CH2:21][CH3:22])=[O:19])=[CH:8][C:9]=1[NH:10]2.P(Cl)(Cl)(Cl)=O>O>[Br:1][C:2]1[CH:14]=[CH:13][C:12]([C:15]#[N:16])=[C:11]2[C:3]=1[C:4]1[CH:5]=[CH:6][C:7]([C:18]([O:20][CH2:21][CH3:22])=[O:19])=[CH:8][C:9]=1[NH:10]2

Participants

Conditions

Temperature: 105 °C

Procedure

Step 1 A suspension of ethyl 5-bromo-8-carbamoyl-9H-carbazole-2-carboxylate (Intermediate 48-1, 2.2 g, 6.09 mmol) in phosphorus oxychloride (45.4 mL, 487 mmol) was heated at 105° C. for 1 h. The suspension was cooled to rt and concentrated to give a brown solid, which was suspended in water. The precipitate was collected by filtration, washed with water and dried to provide ethyl 5-bromo-8-cyano-9H-carbazole-2-carboxylate (2.05 g, 98%) as light brown solid. 1H NMR (400 MHz, DMSO-d6) δ 12.78 (s, 1H) 8.71 (d, J=8.57 Hz, 1H) 8.24 (s, 1H) 7.95 (d, J=8.57 Hz, 1H) 7.89 (d, J=8.13 Hz, 1H) 7.61 (d, J=8.13 Hz, 1H) 4.39 (q, J=7.10 Hz, 2H) 1.37 (t, 2H). Mass spectrum m/z 360, 362 (M+NH4)+.

Workup

temperatureThe suspension was cooled to rt
concentrationconcentrated
customto give a brown solid, which
filtrationThe precipitate was collected by filtration
washwashed with water
customdried

Sources & evidence

ORD record: ord-89deb98d245a4ba0b213ef751e936553
Source dataset: uspto-grants-2013_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08362065B2

Reaction notes

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