反应详情

60.4 g (2.02 mol) of 80% strength sodium hydride in white oil are suspended in 2 liters of tetrahydrofuran and 311.8 g (2.02 mol) of tert.-butyl 2-cyanopropionate are added dropwise at 20°-30° C. During the course of 45 minutes this clear solution is added dropwise to a solution of 298 g (2.0 mol) of 3,6-dichloropyridazine and the mixture is heated under reflux for 2 hours. 317 ml of acetic acid are then added and the solvent is removed in vacuo. The residue is taken up in a mixture of 6,400 ml of acetic acid, 250 ml of acetic anhydride and 32 g of p-toluenesulfonic acid monohydrate, heated under reflux for 3 hours and again brought to dryness in vacuo. The residue is suspended in a little water, adjusted to pH 5 with sodium hydroxide solution and the water removed by evaporation. The residue is extracted hot using ethyl acetate. 99.7 g (33% of theory) of crude product are thus obtained, which can be employed for the following reaction without further processing.

1. temperaturethe mixture is heated
2. temperatureunder reflux for 2 hours
3. customthe solvent is removed in vacuo
4. additionThe residue is taken up in a mixture of 6,400 ml of acetic acid, 250 ml of acetic anhydride and 32 g of p-toluenesulfonic acid monohydrate
5. temperatureheated
6. temperatureunder reflux for 3 hours
7. customthe water removed by evaporation
8. extractionThe residue is extracted hot
9. custom99.7 g (33% of theory) of crude product are thus obtained
10. customwhich can be employed for the following reaction without further processing