899350-32-4

3-Bromo-benzenebutanoic Acid is a reactant used in the preparation of pyrrolo-(di)-benzazocinones via an intramolecular cyclization of N-acyliminium ions formed from 4,4-diethyoxybutyl amides (Erratum)

Step 2: Water (0.5 mL), hydrazine monohydrate (1.5 mL) and potassium hydroxide (3.34 g) were sequentially added to a solution of 4-(3-bromophenyl)-4-oxobutanenitrile (3.1 g, 13.0 mmol) obtained by isolation in ethylene glycol (22 mL). The reaction mixture was heated to 195 °C and the progress of the reaction was monitored by LCMS until the reaction was complete. Upon completion of the reaction, the mixture was cooled to room temperature, diluted with water and the pH was adjusted with 2N HCl to about 2. Subsequently, the reaction mixture was extracted with EtOAc and the organic phase was dried with anhydrous MgSO4, filtered and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography with the eluent being a hexane solution of 0 to 30% acetone, resulting in 2.9 g of the target product 3-bromophenylbutyric acid.

[1] Patent: WO2014/99503, 2014, A1. Location in patent: Paragraph 0098