Acetic Anhydride → 6-Bromo-1H-indole-3-carbonitrile

Reaction equation

[Br:1][C:2]1[CH:10]=[C:9]2[C:5]([C:6]([CH:11]=O)=[CH:7][NH:8]2)=[CH:4][CH:3]=1.[NH2:13]O.Cl.CC(OC(C)=O)=O>N1C=CC=CC=1>[Br:1][C:2]1[CH:10]=[C:9]2[C:5]([C:6]([C:11]#[N:13])=[CH:7][NH:8]2)=[CH:4][CH:3]=1

Participants

Procedure

To a solution of 6-bromo-1H-indole-3-carbaldehyde (1.2 g, 5.36 mmol) in pyridine (10 mL) was added NH2OH.HCl (0.424 g, 6.11 mmol) portionwise and the resulting mixture was stirred at rt for 1.5 h. 25 mL of Ac2O was added and the mixture was heated at reflux overnight. After this time the reaction mixture was cooled to rt and poured into ice. The resulting solid was filtered and the product was purified by flash column chromatography to give 6-bromo-1H-indole-3-carbonitrile slightly impure but was used for the next step. Mass Spectrum (ESI) m/e=222 (M+1).