反应详情

15.8 g (60 mmols) of ethyl 2-nitrobenzylidene-acetoacetate are boiled under reflux with 11.5 g (66 mmols) of benzamidine hydrochloride hydrate and 5.91 g (72 mmols) of anhydrous sodium acetate in 180 ml of ethanol for 18 hours. The mixture is cooled and concentrated. The evaporation residue obtained is taken up in a mixture of ethyl acetate, water and 100 ml of 1 N hydrochloric acid and the mixture is shaken vigorously and left to separate. The ethyl acetate phase is extracted once more with 100 ml of 1 N hydrochloric acid and the combined aqueous phases are extracted once by shaking with ether and then rendered alkaline with concentrated sodium hydroxide solution. The mixture is extracted twice with ethyl acetate and the combined ethyl acetate phases are washed with water, dried and concentrated. The resulting oil is stirred with a little cold acetonitrile; the crystals formed are filtered off with suction and washed with cold acetonitrile. 12.2 g (55.71% of theory) of a slightly yellow-colored product of melting point 102°-105° C. are obtained.

1. temperatureThe mixture is cooled
2. concentrationconcentrated
3. customThe evaporation residue obtained
4. waitleft
5. customto separate
6. extractionThe ethyl acetate phase is extracted once more with 100 ml of 1 N hydrochloric acid
7. extractionthe combined aqueous phases are extracted once
8. stirringby shaking with ether
9. extractionThe mixture is extracted twice with ethyl acetate
10. washthe combined ethyl acetate phases are washed with water
11. customdried
12. concentrationconcentrated
13. stirringThe resulting oil is stirred with a little cold acetonitrile
14. customthe crystals formed
15. filtrationare filtered off with suction
16. washwashed with cold acetonitrile
17. custom12.2 g (55.71% of theory) of a slightly yellow-colored product of melting point 102°-105° C. are obtained