Dichloromethane → (E)-3-(7-oxo-5,6,7,8-tetrahydro-1,8-naphthyridin-3-yl)acrylic Acid Hydrochloride
Reaction equation
FC(F)(F)C(O)=O.[O:8]=[C:9]1[NH:18][C:17]2[N:16]=[CH:15][C:14](/[CH:19]=[CH:20]/[C:21]([O:23]C(C)(C)C)=[O:22])=[CH:13][C:12]=2[CH2:11][CH2:10]1.[Cl:28]CCl>>[ClH:28].[O:8]=[C:9]1[NH:18][C:17]2[N:16]=[CH:15][C:14](/[CH:19]=[CH:20]/[C:21]([OH:23])=[O:22])=[CH:13][C:12]=2[CH2:11][CH2:10]1Participants
4
Procedure
Trifluoroacetic acid (31 mL) was added to a suspension of tert-butyl (E)-3-(7-Oxo-5,6,7,8-tetrahydro-1,8-naphthyridin-3-yl)-acrylate (1.1 g, 3.76 mmol; which may be prepared as described in D1, Step 6) in dichloromethane (31 mL). The reaction mixture was stirred at room temperature for 1 hour and concentrated to dryness. The resulting residue was solubilized in a solution of hydrochloric acid in dioxane (4N, 60 mL). After 10 minutes stirring at room temperature, the precipitate was filtered and washed with diethyl ether to afford the title product as a pale yellow solid (4.5 g, quantitative).