反应详情

2-Cyclopropyl-6-[1-(ethoxy)ethenyl]-7-fluoro-5-methyl-1,3-benzoxazole-4-carbonitrile (I-78) (1.0 g, 3.49 mmol) was dissolved in tetrahydrofuran (10 ml), aqueous 1 N hydrochloric acid solution (2.0 ml) was added, followed by stirring at room temperature for 19 hours. At this point in time, it was known that a mixture with an oxazole-opened compound is given, and for complete ring opening, methanol (5 ml) was added followed by stirring overnight at room temperature. The solvent was concentrated under reduced pressure, ethyl acetate was added to the resulting residue, followed by fractionation with water.

1. stirringby stirring overnight at room temperature
2. concentrationThe solvent was concentrated under reduced pressure, ethyl acetate
3. additionwas added to the resulting residue