Diisopropyl Ether → (E)-3-[2-(4-Oxo-4H-1,3-benzothiazin-2-yl)-4-pyridyl]acrylic acid
Reaction equation
[O:1]=[C:2]1[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]=2[S:5][C:4]([C:12]2[CH:17]=[C:16](/[CH:18]=[CH:19]/[C:20]([O:22]C(C)(C)C)=[O:21])[CH:15]=[CH:14][N:13]=2)=[N:3]1.C(OC(C)C)(C)C>FC(F)(F)C(O)=O>[O:1]=[C:2]1[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]=2[S:5][C:4]([C:12]2[CH:17]=[C:16](/[CH:18]=[CH:19]/[C:20]([OH:22])=[O:21])[CH:15]=[CH:14][N:13]=2)=[N:3]1Participants
4
Procedure
tert-Butyl (E)-3-[2-(4-oxo-4H-1,3-benzothiazin-2-yl)-4-pyridyl]acrylate (0.14 g, 0.44 mmol) was dissolved in trifluoroacetic acid (2.0 ml), and the mixture was stirred at room temperature for 2.5 hrs. Isopropyl ether was added to the reaction mixture to precipitate crystals, which were collected by filtration and recrystallized from tetrahydrofuran-ethanol to give the titled compound (0.088 g, 64%) as white crystals.