反应详情

Pyridine-hydrobromide-perbromide (48 g) was added to a solution of ethyl acetoacetate (19.4 g) in anhydrous methylene chloride (500 ml) at room temperature in 20 minutes. The mixture was stirred for 2 hours and then added dropwise to a solution of dimethylamine (48.8 g) in anhydrous methylene chloride (100 ml) at -15°-0° in 1 hr. The resulting mixture was cooled to -20° and ammonia was bubbled through the mixture under stirring for 1 hr and for 2 hr at room temperature. The reaction went to completion, by leaving the mixture overnight at about 5° C. After evaporation of the solvent the residue was treated with ether the solid was filtered off and the solution evaporated, to yield a brown oil, which was purified by column chromatography on silica gel to give the title compound (10.8 g) as an orange oil.

1. temperatureThe resulting mixture was cooled to -20°
2. customammonia was bubbled through the mixture
3. stirringunder stirring for 1 hr and for 2 hr at room temperature
4. customby leaving the mixture overnight at about 5° C
5. customAfter evaporation of the solvent the residue
6. additionwas treated with ether the solid
7. filtrationwas filtered off
8. customthe solution evaporated
9. customto yield a brown oil, which
10. customwas purified by column chromatography on silica gel