反应详情

温度

200 °C

A solution of 33.0 g. (0.096 mole) of ethyl 3-carboxy-1,4-dimethyl-5-(p-toluoyl)-pyrrole-2-acetate in 200 ml. of quinoline with 0.1 g. copper chromite added is heated under nitrogen for 6 hours at 200° C., then for 30 minutes at 220° C. The quinoline is distilled off in vacuo. The residue is dissolved in ether and washed successively with dilute hydrochloric acid, dilute sodium hydroxide, and brine; dried over magnesium sulfate; and the solvent evaporated in vacuo to give a brown oily residue which crystallizes. It is recrystallized from methanol, sublimed at 150° C. (0.025 mm/Hg) and recrystallized from hexane to give ethyl 1,4-dimethyl-5-(p-toluoyl)-pyrrole-2-acetate as a white solid, m.p. 90-93° C.

1. distillationThe quinoline is distilled off in vacuo
2. dissolutionThe residue is dissolved in ether
3. washwashed successively with dilute hydrochloric acid, dilute sodium hydroxide, and brine
4. dry with materialdried over magnesium sulfate
5. customand the solvent evaporated in vacuo
6. customto give a brown oily residue which
7. customcrystallizes
8. customIt is recrystallized from methanol
9. customsublimed at 150° C.
10. customrecrystallized from hexane