反应详情

Trifluoroacetic acid (2 ml) was added to a solution of tert-butyl 3-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-yl) propionate prepared in Example 44 (0.72 g, 2.42 mmol) in methylene chloride (14 ml) followed by stirring at room temperature for 30 minutes. The reaction mixture was concentrated under reduced pressure. The residue was crystallized from ethanol-methylene chloride to afford 3-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-yl)propionic acid (0.30 g, 51%) as a light yellow solid.

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. customThe residue was crystallized from ethanol-methylene chloride