tert-butyl (E)-3-(7-oxo-5,6,7,8-tetrahydro-1,8-naphthyridin-3-yl)acrylate → (E)-3-(7-oxo-5,6,7,8-tetrahydro-1,8-naphthyridin-3-yl)acrylic Acid Hydrochloride
Reaction equation
[O:1]=[C:2]1[NH:11][C:10]2[N:9]=[CH:8][C:7](/[CH:12]=[CH:13]/[C:14]([O:16]C(C)(C)C)=[O:15])=[CH:6][C:5]=2[CH2:4][CH2:3]1.C(O)(C(F)(F)F)=O.C(Cl)[Cl:29]>>[ClH:29].[O:1]=[C:2]1[NH:11][C:10]2[N:9]=[CH:8][C:7](/[CH:12]=[CH:13]/[C:14]([OH:16])=[O:15])=[CH:6][C:5]=2[CH2:4][CH2:3]1Participants
3
Procedure
To tert-butyl (E)-3-(7-oxo-5,6,7,8-tetrahydro-1,8-naphthyridin-3-yl)acrylate (7.0 g, 25.5 mmole) was added 1:1 TFA/CH2Cl2 (100 mL). The reaction was stirred for 30 min, then was concentrated under vacuum. The residue was suspended in 4 N HCl/dioxane (100 mL), triturated, and concentrated to dryness. The resulting solid was triturated with Et2O, collected, and dried under vacuum to give the title compound (6.55 g, 100%) as a off-white solid: 1H NMR (400 MHz, d6-DMSO) δ 10.72 (s, 1 H), 8.35 (d, J=2.0 Hz, 1 H), 8.04 (s, 1H), 7.54 (d, J=16.0 Hz, 1 H), 6.51 (d, J=16.0 Hz, 1 H), 2.91 (t, 2 H), 2.53 (t, 2 H); MS (ES) m/e 219.0 (M+H)+.