4-Chlorobenzylamine → N-(4-Chlorobenzyl)-6-(3-hydroxy-1-propynyl)-1-methyl-4-oxo-1,4-dihydro[1,5]-naphthyridine-3-carboxamide

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Reaction Steps

Trimethylaluminum (2M in toluene, 42 μL) is added dropwise to a room temperature solution of 4-chlorobenzylamine (17 μL) in CH2Cl2 (1 mL) under nitrogen. The solution is stirred for 5 minutes before the addition in one portion of ethyl 6-(3-hydroxy-1-propynyl)-1-methyl4-oxo-1,4-dihydro[1,5]naphthyridine-3-carboxylate (Preparation 60, 20 mg). The resulting suspension is stirred at room temperature for 3.5 h. The reaction mixture is partitioned with dil. aq. HCl (2 mL) and extracted with CH2Cl2 (2×2 mL). After drying over MgSO4, the extracts are concentrated under vacuum. The crude residue is purified by flash chromatography (9 g silica, 10% methanol/CH2Cl2) to give 14 mg (52%) of the title compound as a It. yellow solid. Physical Characteristics: Rf (15% methanol/CH2Cl2)=0.53; 1H NMR (DMSO-d6) δ 10.32, 8.90, 8.31, 7.90, 7.40, 7.36, 5.5, 4.58, 4.39, 4.01; HRMS (FAB) m/z 382.0963 (C20H16ClN3O3+H). Anal. Found (C20H16ClN3O3.0.24 H2O): C, 62.21; H, 4.21; N, 10.75.

Provenance & Evidence