反应详情

To a stirred solution of 13 g of methyl 2-p-chlorophenyl-5-(2,5-dimethylphenoxy)-4-oxazoleacetate prepared in Example 4 in 150 ml of acetone at room temperature was dropwise added a 15 ml aqueous solution of 2.0 g of sodium hydroxide. The mixture was further stirred for 3.5 hours. After the solvent was evaporated under reduced pressure, water was added to the remaining aqueous solution. The resulting solution was cooled and acidified to pH 3 with hydrochloric acid. The crystalline precipitate was filtered off and recrystallized from ethanol to give 9.05 g of the title compound as bulky needles, melting at 185° C.

1. customAfter the solvent was evaporated under reduced pressure, water
2. additionwas added to the remaining aqueous solution
3. temperatureThe resulting solution was cooled
4. filtrationThe crystalline precipitate was filtered off
5. customrecrystallized from ethanol