反应详情

47 μl (0.47 mmol) of piperidine are added dropwise to a solution of 3.02 g (15.79 mmol) of the compound from Example 36A and 1.09 g (16.42 mmol) of malonodinitrile in 100 ml of ethanol, and the reaction mixture is stirred at +78° C. for 3.5 h. During this time, the colour of the solution changes to orange-red. After cooling to RT, the solution is allowed to stand without stirring for 20 h. A colourless precipitate is formed. Using a rotary evaporator, the crude suspension is concentrated to half of its original volume, and the crystallization is completed with cooling in an ice bath. The resulting precipitate is filtered off with suction and washed twice with in each case 20 ml of ethanol and twice with in each case 20 ml of methyl tert-butyl ether.

1. stirringwithout stirring for 20 h
2. customA colourless precipitate is formed
3. customa rotary evaporator
4. concentrationthe crude suspension is concentrated to half of its original volume
5. customthe crystallization
6. temperaturewith cooling in an ice bath
7. filtrationThe resulting precipitate is filtered off with suction
8. washwashed twice with in each case 20 ml of ethanol and twice with in each case 20 ml of methyl tert-butyl ether