Sodium Bicarbonate → 6-{[(2-{4-[6-(methyloxy)-1,5-naphthyridin-4-yl]-2-oxo-1-piperazinyl}ethyl)amino]methyl}-2H-pyrido[3,2-b][1,4]thiazin-3(4H)-one

Participants

Reaction Steps

To a solution of 1-(2-aminoethyl)-4-[6-(methyloxy)-1,5-naphthyridin-4-yl]-2-piperazinone (46 mg, 0.15 mmol) in DCM-EtOH (2 mL, 1:1) were added NaHCO3 (32 mg, 0.38 mmol) and 3-oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]thiazine-6-carbaldehyde (29 mg, 0.15 mmol). After 12 h, NaBH(OAc)3 (38 mg, 0.15 mmol) was added. After an additional 2 h the solution was partitioned between NaHCO3 (sat)-DCM. The aqueous phase was extracted several times with DCM and the combined organic fractions were dried (Na2SO4), concentrated and purified via column chromatography (silica, 0-7% MeOH in DCM (1% NH4OH)) yielding the title compound (48 mg, 67%) as a yellow solid: LCMS (ES) m/e 480 (M+H)+; 1H NMR (CD3OD, 400 MHz) δ 8.44 (d, J=5.3 Hz, 1H), 8.12 (d, J=9.0 Hz, 1H), 7.63 (d, J=7.8 Hz, 1H), 7.17 (d, J=9.0 Hz, 1H), 7.00 (d, J=7.8 Hz, 1H), 6.96 (d, J=5.2 Hz, 1H), 4.21 (s, 2H), 4.19-4.22 (m, 2H), 4.03 (s, 3H), 3.82 (s, 2H), 3.69-3.74 (m, 4H), 3.67 (s, 2H), 2.90-2.93 (m, 2H).

Provenance & Evidence