反应详情

A mixture of 9.8 parts of ethyl chloroacetate and 20 parts of dimethylformamide is added to a mixture, warmed to 145° C., of 5.8 parts of 1,4-diketo-3,6-diphenylpyrrolo-[3,4-c]-pyrrole, 8.5 parts of sodium carbonate and 60 parts of dimethylformamide in the course of 30 minutes. The brown-yellow solution formed is subsequently stirred at 140°-145° C. for 30 minutes, cooled and poured onto 1,000 parts of water of 15° C. After the mixture has been left to stand at 20° C. for one hour, the aqueous phase is poured off and the crude product is heated to the boiling point with 200 parts of ethanol. The suspension formed is filtered at 20° C. and the product is washed with ethanol and then with water of 90° C. and dried. 5.6 parts of a yellow product of melting point 204°-208° C. are obtained. Pure 1,4-diketo-2,5-di-(carboethoxymethyl)-3,6 -diphenylpyrrolo-[3,4-c]-pyrrole of the following formula of melting point 209°-210° C. and M+ 460 is obtained by crystallisation from toluene. ##STR27##

1. additionis added to a mixture
2. customThe brown-yellow solution formed
3. temperaturecooled
4. waitAfter the mixture has been left
5. waitto stand at 20° C. for one hour
6. additionthe aqueous phase is poured off
7. customThe suspension formed
8. filtrationis filtered at 20° C.
9. washthe product is washed with ethanol
10. dry with materialwith water of 90° C. and dried
11. custom5.6 parts of a yellow product of melting point 204°-208° C. are obtained