反应详情

Solution of 5-chloro-2-phenyl-oxazole-4-carboxylic acid ethyl ester (92 mg, 0.37 mmol) in a mixture solution of tetrahydrofuran, methanol and water (3:1:1, 5 mL) was treated with lithium hydroxide monohydride (44 mg, 1.1 mmol) at room temperature for two hours. After the reaction was complete, solvent was evaporated. To the residue, water was added, and pH value of the aqueous layer was adjusted to ˜1-2 by addition of dilute hydrochloride acid (1N). The white precipitation was collected by centrifugation to give 5-chloro-2-phenyl-oxazole-4-carboxylic acid (73 mg, 88%). LCMS calcd for C10H6ClNO3 (m/e) 223, obsd 224 (M+H).

1. customsolvent was evaporated
2. additionTo the residue, water was added
3. additionpH value of the aqueous layer was adjusted to ˜1-2 by addition of dilute hydrochloride acid (1N)
4. customThe white precipitation
5. customwas collected by centrifugation