反应详情

A solution of 67 g. (0.314 mole) of p-bromophenylglyoxal in 300 ml. of dry toluene is added dropwise over 1 1/2 hours to a stirrred suspension of 84 g. (0.6 mole) of anhydrous aluminum chloride in 1.25 1. of dry toluene cooled in an ice-bath. Stirring in the cold is continued for 5 hours and the mixture then is held at 5°-10° C. overnight. The mixture is poured into about 2 1. of ice and 6N hydrochloric acid. The aqueous phase is separated and re-extracted with three portions of benzene. The combined, washed and dried organic extracts are concentrated under reduced pressure to a volume of about 200 ml. Dilution with 150 ml. of petroleum ether precipitates the white crystalline product, m.p. 80°-82° C. Repeated recrystallization from 60% ethanol affords the analytical sample, m.p. 82°-83.5° C.

1. waitthe mixture then is held at 5°-10° C. overnight
2. additionThe mixture is poured into about 2 1
3. customThe aqueous phase is separated
4. extractionre-extracted with three portions of benzene
5. washwashed
6. concentrationdried organic extracts are concentrated under reduced pressure to a volume of about 200 ml
7. customof petroleum ether precipitates the white crystalline product, m.p. 80°-82° C
8. customrecrystallization from 60% ethanol
9. customaffords the analytical sample, m.p. 82°-83.5° C.