Ethanol → Diethyl 5,8-dihydroxy-6,7-quinolinedicarboxylate

Participants

Reaction Steps

To a mechanically stirred solution of diethyl pyridine-2,3-dicarboxylate 1 (86%, 85.6 g, 330 mmol) and diethyl succinate (70 ml, 414 mmol) in toluene (100 ml) at 95 C was added slowly a solution of NaOEt in EtOH (21%, 311 ml, 825 mmol) and this mixture was stirred at reflux o.n. It was then poured into an ice cold solution of sat NH4Cl (1.5 L) containing 60 ml AcOH. The products were extracted into EtOAc, dried over Na2SO4 and this solution was filtered through a pad of silica (400 ml) and concentrated to dryness. The residue was triturated into ether:hexane 1:2, the solid filtered, washed with hexane and air dried to yield 77.3 g (77% yield) of 2.

Provenance & Evidence