Hydrochloric Acid → 3-Ethoxy-2-methyl-5-[4-(2-pyridyloxy)anilino]-1,8-naphthyridine dihyrochloride trihydrate

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Reaction Steps

A mixture of 5-chloro-3-ethoxy-2-methyl-1,8-naphthyridine (2.0 g) and 4-(2-pyridyloxy)aniline (1.67 g) in IMS (50 ml) was boiled under reflux for 3 hours and then allowed to stand at ambient temperature overnight. The mixture was evaporated under reduced pressure and the residue recrystallised from IMS to give a solid which was dissolved in hot IMS and then cooled in an ice bath while hydrogen chloride gas was bubbled through. The mixture was evaporated to dryness and the residue was recrystallised from IMS to give 3-ethoxy-2-methyl-5-[4-(2-pyridyloxy)anilino]-1,8-naphthyridine dihyrochloride trihydrate, m.p. 244°-247° C. Borderline active (1/1) at 30 mg/kg.

Provenance & Evidence