3-Methyl-2-sulfanylbenzoic acid → tert-Butyl 3-[6-(8-methyl-4-oxo-4H-1,3-benzothiazin-2-yl)-2-pyridyl]propanoate
Reaction equation
[CH3:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:4]([C:5]([OH:7])=O)[C:3]=1[SH:11].[C:12]([C:14]1[N: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][CH:15]=1)#[N:13]>N1C=CC=CC=1>[CH3:1][C:2]1[C:3]2[S:11][C:12]([C:14]3[N: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][CH:15]=3)=[N:13][C:5](=[O:7])[C:4]=2[CH:8]=[CH:9][CH:10]=1Participants
4
Procedure
A mixture of 3-methylthiosalicylic acid (2.52 g, 15 mmol), tert-butyl 3-(6-cyano-2-pyridyl)propanoate (2.32 g, 10 mmol) and pyridine (30 ml) was refluxed under nitrogen atmosphere for 20 hrs and concentrated under reduced pressure. The residue was subjected to a silica gel (100 g) column chromatography. The titled compound (2.79 g, 73%) was given from the fractions eluted with hexane-ethyl acetate (2:1, v/v), which were recrystallized from ethyl acetate-isopropyl ether.