4-Chloro-2-sulfanylbenzoic acid → tert-Butyl 3-[6-(7-chloro-4-oxo-4H-1,3-benzothiazin-2-yl)-2-pyridyl]propanoate
Reaction equation
[C:1]([C:3]1[N:8]=[C:7]([CH2:9][CH2:10][C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[CH:6]=[CH:5][CH:4]=1)#[N:2].[Cl:18][C:19]1[CH:20]=[C:21]([SH:28])[C:22](=[CH:26][CH:27]=1)[C:23](O)=[O:24]>N1C=CC=CC=1>[Cl:18][C:19]1[CH:27]=[CH:26][C:22]2[C:23](=[O:24])[N:2]=[C:1]([C:3]3[N:8]=[C:7]([CH2:9][CH2:10][C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[CH:6]=[CH:5][CH:4]=3)[S:28][C:21]=2[CH:20]=1Participants
4
Procedure
tert-Butyl 3-(6-cyano-2-pyridyl)propanoate (1.6 g, 6.9 mmol) and 4-chlorothiosalicylic acid (2.6 g, 13.7 mmol) were dissolved in pyridine (15 ml), and the mixture was refluxed for 13 hrs. The solvent was evaporated. The residue was subjected to a silica gel column chromatography. The fractions eluted with hexane-ethyl acetate (3:1, v/v) were collected, concentrated and recrystallized from hexane-ethyl acetate to give the titled compound (1.4 g, 51%) as pale yellow crystals.