反应详情

Ethyl 1-(2-chloro-6-fluorophenyl)-1-hydroxymethanecarboximidate hydrochloride (15.0 g., 0.056 mole) and triethylamine (16.8 g., 23.3 ml., 0.167 mole) were taken into 560 ml. of tetrahydrofuran and cooled to 0° C. Phosgene was bubbled through the reaction mixture for 35 minutes. It was then stirred for 2.5 hours at room temperature, poured into 600 cc. of crushed ice and extracted with three portions of ethyl acetate. The combined extracts were washed with water, washed with brine, dried over anhydrous magnesium sulfate, filtered and evaporated in vacuo to product (14.4 g.). Recrystallization from toluene afforded purified 5-(2-chloro-6-fluorophenyl)oxazolidine-2,4-dione [10.7 g., 83%; m.p. 153°-155° C.; ir (KBr) 1820, 1740 cm-1 ].

1. customPhosgene was bubbled through the reaction mixture for 35 minutes
2. additionpoured into 600 cc
3. extractionof crushed ice and extracted with three portions of ethyl acetate
4. washThe combined extracts were washed with water
5. washwashed with brine
6. dry with materialdried over anhydrous magnesium sulfate
7. filtrationfiltered
8. customevaporated in vacuo to product (14.4 g.)
9. customRecrystallization from toluene
10. customafforded
11. custompurified 5-(2-chloro-6-fluorophenyl)oxazolidine-2,4-dione [10.7 g., 83%; m.p. 153°-155° C.; ir (KBr) 1820, 1740 cm-1 ]