4-Chloro-2-sulfanylbenzoic acid → tert-Butyl 3-[2-(7-chloro-4-oxo-4H-1,3-benzothiazin-2-yl)-4-pyridyl]propanoate
Reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([SH:11])[C:5](=[CH:9][CH:10]=1)[C:6]([OH:8])=O.[C:12]([C:14]1[CH:19]=[C:18]([CH2:20][CH2:21][C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])[CH:17]=[CH:16][N:15]=1)#[N:13]>N1C=CC=CC=1>[Cl:1][C:2]1[CH:10]=[CH:9][C:5]2[C:6](=[O:8])[N:13]=[C:12]([C:14]3[CH:19]=[C:18]([CH2:20][CH2:21][C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])[CH:17]=[CH:16][N:15]=3)[S:11][C:4]=2[CH:3]=1Participants
4
Procedure
4-Chlorothiosalicylic acid (2.3 g, 12.2 mmol) and tert-butyl 3-(2-cyano-4-pyridyl)propanoate (1.4 g, 6.0 mmol) were dissolved in pyridine (20 ml), and the mixture was refluxed for 16 hrs. The solvent was evaporated and the residue was subjected to a silica gel column chromatography. The fraction eluted with hexane-ethyl acetate (2:1, v/v) were collected, concentrated and recrystallized from hexane-tetrahydrofuran to give the titled compound (1.3 g, 52%) as white crystals.