Acetic Acid → 9-Bromo-5-methyl-4-oxo-3-phenyl-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetic acid

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Reaction Steps

A solution of 4.8 g (12.2 mmol) of 9-bromo-5-methyl-4-oxo-3-phenyl-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetonitrile in a mixture of 190 ml of acetic acid and of 50 ml of concentrated hydrochloric acid is heated at reflux for 6 h. The solution is concentrated under reduced pressure and the residue is taken up in a mixture of dichloromethane and of water. Basification is carried out with 30% sodium hydroxide solution, separation is carried out by settling and extraction is carried out with dichloromethane. The aqueous phase is acidified with concentrated hydrochloric acid while cooling with an ice bath. The precipitate is collected by filtration, washed with water and dried under reduced pressure. 3.1 g (7.5 mmol) of solid are obtained.

Provenance & Evidence