Hydrochloric Acid → 3-Aminomethyl-4-oxo-1-phenyl-7-trifluoromethyl-1,4-dihydro-[1,8]naphthyridine-2-carboxylic acid methyl ester hydrochloride

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Reaction Steps

In a 100 mL pear-shaped flask, 3-azidomethyl-4-oxo-1-phenyl-7-trifluoromethyl-1,4-dihydro-[1,8]naphthyridine-2-carboxylic acid methyl ester (490 mg, 1.21 mmol), platinum (IV) oxide (100 mg, 0.440 mmol) and a 4N HCl in 1,4-dioxane (2.4 g, 2 mL) were combined with ethyl acetate (12 mL) to give a brown suspension which was hydrogenated at atmospheric pressure at 25° C. for 11 hr. The reaction mixture was diluted with methanol (200 mL), stirred for 1 hr at room temperature, filtered through a small celite pad, and concentrated under vacuum to give 3-aminomethyl-4-oxo-1-phenyl-7-trifluoromethyl-1,4-dihydro-[1,8]naphthyridine-2-carboxylic acid methyl ester hydrochloride (0.54 g, 107% crude yield) as a light brown solid. Material was used without any further purification. 1H NMR (DMSO-d6) δ ppm 8.93 (d, J=8.2 Hz, 1H) 8.21 (br. s., 2H) 8.04 (d, J=8.2 Hz, 1H) 6.80-7.72 (m, 4H) 3.88 (br. s., 2H) 3.54 (s, 3H). MS calcd. for C18H14F3N3O3 [(M+H)+] 378.0, obsd. 378.0, [(M+H-NH3)+] 361.0, obsd. 361.0, [(M+H-NH3+CH3CN)+] 402.0, obsd. 402.0.

Provenance & Evidence