3,4-Diaminopyridine → HCID 178525444, compound

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Reaction Steps

To 1-{1-[4-(5-carboxypentyloxy)benzoyl]-4-piperidinyl}-3,4-dihydrocarbostyril (2.00 g) are added 3,4-diaminopyridine (0.47 g), phosphorus pentoxide (1.00 g) and methanesulfonic acid (7.0 ml) and the mixture is stirred with heating at 100°-120° C. for 3 hours. After cooling, the reaction solution is poured into ice-water (30 ml) and the mixture is adjusted to around pH 11 with aqueous sodium hydroxide solution and extracted with dichloromethane. The extract is dried with magnesium sulfate and the solvent is distilled off. The resulting residue is purified by silica gel column chromatography (solvent: dichloromethane:methanol=20:1→9:1) to give 1-{1-[4-(5-(imidazo[4,5-c]pyridine-2-yl)carboxypentyloxy)benzoyl]-4-piperidinyl]-3,4-dihydrocarbostyril (1.32 g) as white amorphous form.

Provenance & Evidence