tert-Butyl (E)-3-[6-(4-oxo-4H-1,3-benzothiazin-2-yl)-2-pyridyl]-2-propenoate → (E)-3-[6-(4-oxo-4H-1,3-benzothiazin-2-yl)-2-pyridyl]-2-propenoic acid

Participants

Reaction Steps

tert-Butyl (E)-3-[6-(4-oxo-4H-1,3-benzothiazin-2-yl)-2-pyridyl]-2-propenoate (0.78 g, 2.0 mmol) was dissolved in trifluoroacetic acid (4.0 ml) under ice cooling condition. The reaction mixture was stirred for 1 hr while it was warmed gradually to room temperature. The reaction mixture was concentrated under reduced pressure to precipitate crystals, which were recrystallized from methanol-diisopropyl ether to give the titled compound (0.60 g, 97%) as white crystals.

Provenance & Evidence