Hydrochloric Acid → (S)-6-methyl-8-((4-methyl-2-(methylamino)pentyl)oxy)benzo[c][2,7]naphthyridin-5(6H)-one

Participants

Reaction Conditions

Reaction Steps

To the solution of (S)-tert-butyl methyl(4-methyl-1-((6-methyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridin-8-yl)oxy)pentan-2-yl)carbamate (180 mg, 0.078 mmol) in dichloromethane (4 mL) cooled to 0° C. was added HCl in ether (4 mL, 4.00 mmol) slowly over a period of 1 min. The reaction mixture was stirred at 0° C. for 5 min then warmed to room temperature and stirred for 4 h. The volatiles were then removed under reduced pressure. The residue was purified via reverse phase HPLC (0.1% TFA in water:acetonitrile) to afford (S)-6-methyl-8-((4-methyl-2-(methylamino)pentyl)oxy)benzo[c][2,7]naphthyridin-5(6H)-one (15 mg, 0.025 mmol, 32% yield) as a yellow solid. LC/MS (ESI) m/e 340.2, [(M+H)+, calcd for C20H26N3O2, 340.2]; LC/MS retention time (method I): tR=1.6 min. HPLC retention time (method A): tR=7.59 min; HPLC retention time (method B): tR=8.08 min. 1H NMR (400 MHz, METHANOL-d4) δ ppm 9.54 (s, 1H), 8.83 (d, J=5.8 Hz, 1H), 8.53 (d, J=8.8 Hz, 1H), 8.46 (d, J=6.0 Hz, 1H), 7.27-7.16 (m, 2H), 4.57 (dd, J=11.3, 3.0 Hz, 1H), 4.44 (dd, J=11.3, 5.3 Hz, 1H), 3.84 (s, 3H), 3.78-3.68 (m, 1H), 2.84 (s, 3H), 1.95-1.78 (m, 2H), 1.75-1.61 (m, 1H), 1.08 (d, J=6.5 Hz, 6H).

Provenance & Evidence