Ethanol → HCID 13885783, compound

Participants

Reaction Steps

A solution of 3.1 g (6.1 mMole) ethyl (±)-2-dibromomethyl-1,4-dihydro-5-isopropoxy-4-phenyl-1,6-naphthyridine-3-carboxylate (Example 4) in 70 ml ethanol is heated to 60° C. and, at this temperature, a solution of 2.1 g (12.4 mMole) silver nitrate in 5 ml water/3 ml ethanol is added dropwise thereto. The reaction mixture is heated under reflux for ten minutes, cooled and the precipitate filtered off, whereafter the filtrate is evaporated. After dilution with dichloromethane, it is washed with water and the organic phase is dried over anhydrous magnesium sulphate and subsequently evaporated in a vacuum. The residue is chromatographed on silica gel with toluene/ethyl acetate (9:1 v/v). The fraction with the Rf of 0.3 is isolated and recrystallized from n-hexane/cyclohexane. There is obtained ethyl (±)-2-formyl-1,4-dihydro-5-isopropoxy-4-phenyl-1,6-naphthyridine-3-carboxylate in the form of yellow crystals; mp 132°-135° C.

Provenance & Evidence