Trifluoroacetic acid → HCID 86624625, compound

Participants

Reaction Steps

To a suspension of [2-(3-hydroxy-phenylcarbamoyl)-ethyl]-carbamic acid tert-butyl ester (4-3) (100 mg, 0.36 mmol) in dichloromethane (2 mL) was added trifluoroacetic acid (1 mL). The suspension immediately turned into clear solution and was stirred at room temperature for 1 hr. The volatile solvents were removed by rotovap evaporation and the oil residue was further dried by vacuum pump over night. The oil residue was re-solubilized in dichloromethane (1 mL) and de-salted with triethylamine (1 mL). After the resulting solution was stirred at room temperature for 1 hr, 4-(5-oxo-3-phenyl-5,6-dihydro-1,6-naphthyridin-2-yl)benzaldehyde (4-5; synthesis shown and described in Reaction Scheme V) (80 mg, 0.25 mmol) was added followed by sodium triacetoxyborohydride (159 mg, 0.75 mmol) after an additional 0.5 hr of stirring at room temperature. The final reaction mixture was stirred at room temperature overnight and then directly purified by HPLC (Phenomenx Synergi column; 20-85% acetonitrile/water+0.1% TFA) to afford the product (4-6) as bright yellow oil: 1H-NMR (500 MHz, d4-CD3OD) δ 8.64 (s, 1H), 7.53-7.48 (m, 5H), 7.30-7.28 (m, 3H), 7.24-7.23 (m, 2H), 7.17 (m, 1H), 7.12 (m, 1H), 6.96 (m, 1H), 6.87 (m, 1H), 6.55 (m, 1H), 4.28 (s, 2H), 3.34 (m, 2H), 2.83 (m, 2H); LRMS, calc'd for C30H26N4O3 (M+1), 491.57; found 491.59.

Provenance & Evidence