Triethylamine → 6-({2-[4-(6-Methoxy-[1,5]naphthyridin-4-yl)phenyl]ethylamino}methyl)-4H-benzo[1,4]thiazin-3-one

Participants

Reaction Steps

To a stirred solution of 2-[4-(6-Methoxy-[1,5]naphthyridin-4-yl)phenyl]ethylamine hydrochloride salt (1.76 mmole) in dry CH2Cl2 (25 mL) and dry EtOH (10 mL) at RT was added triethylamine (0.74 mL, 5.28 mmole) and 3-oxo-3,4-dihydro-2H-benzo[1,4]thiazine-6-carboxaldehyde (0.34 g, 1.76 mmole). After 24 h, the reaction contents were concentrated and dried under high vacuum. To a stirred solution of the crude imine in dry EtOH (25 mL) at RT was added NaBH4 (0.66 g, 1.76 mmole). After 24 h, the reaction solution was concentrated under vacuum and to the residue was added 1M HCl (5 mL) and EtOAc (50 mL): After stirring for 1 h, 6M NaOH (1 mL) was added and the organic layer was separated, dried (Na2SO4) and concentrated. Purification on silica (CHCl3/MeOH, 9:1 containing 5% NH4OH) afforded the title compound (0.55 g, 69%) as light yellow solid: 1H NMR (400 MHz, CD3OD) δ 9.11 (d, J=4.5 Hz, 1H), 8.57 (d, J=9.1 Hz, 1H), 8.27 (d, J=4.5 Hz, 1H), 8.14 (m, 2H), 7.90 (s, 2H), 7.61 (m, 3H), 7.46 (d, J=7.1 Hz, 1H), 7.22 (m, 2H), 5.52 (m, 2H), 4.23 (s, 2H), 4.08 (s, 3H), 3.68 (s, 2H), 3.19 (m, 2H). LC-MS (ES) m/e 457 (M+H)+.

Provenance & Evidence