3-Methyl-2-sulfanylbenzoic acid → tert-Butyl 6-(8-methyl-4-oxo-4H-1,3-benzothiazin-2-yl)-2-pyridinecarboxylate
Reaction equation
[C:1]([C:3]1[N:8]=[C:7]([C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])[CH:6]=[CH:5][CH:4]=1)#[N:2].[CH3:16][C:17]1[CH:25]=[CH:24][CH:23]=[C:19]([C:20](O)=[O:21])[C:18]=1[SH:26]>N1C=CC=CC=1>[CH3:16][C:17]1[C:18]2[S:26][C:1]([C:3]3[N:8]=[C:7]([C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])[CH:6]=[CH:5][CH:4]=3)=[N:2][C:20](=[O:21])[C:19]=2[CH:23]=[CH:24][CH:25]=1Participants
4
Procedure
tert-Butyl 6-cyano-2-pyridinecarboxylate (3.2 g, 15 mmol) and 3-methylthiosalicylic acid (4.7 g, 28 mmol) were dissolved in pyridine (40 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 fractions eluted with hexane-tetrahydrofuran (2:1, v/v) were collected, concentrated and recrystallized from hexane-tetrahydrofuran to give the titled compound (3.1 g, 56%) as pale yellow crystals.