Benzyl 2-benzyl-4-oxo-3,4-dihydropyridine-1(2H)-carboxylate → HCID 21970317, compound

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Reaction Steps

150 g (0.467 mol) of 2-benzyl-N-benzyloxycarbonyl-2,3-dihydro-4-(1H)-pyridone in 1.5 l of methanol are hydrogenated with 7.5 g of Pd/C (10%) as catalyst, then 50 g of Raney nickel and a further 200 ml of methanol are added, and hydrogenation is left to go to completion. Filtration is followed by evaporation in a rotary evaporator, and the brownish oil is chromatographed on silica gel with methylene chloride/methanol/conc. ammonia (60:10:1). The title compound is obtained as a semi-crystalline mass which is used further without additional purification. Crystallisation of a sample from ether/hexane yielded white crystals of melting point 111°-112°. TLC: methylene chloride/methanol/conc. ammonia (40:10:1) Rf =0.55, FD-MS: M+ =191.

Provenance & Evidence