Dimethylformamide → 2-Chloro-5-methylpyridine-3-carbaldehyde
Reaktionsgleichung
CN(C)C=[O:4].O=[C:7]([Cl:13])OC(Cl)(Cl)Cl.[CH2:14]([N:21](C=CC)C(=O)C)[C:15]1[CH:20]=C[CH:18]=[CH:17][CH:16]=1>>[Cl:13][C:7]1[C:17]([CH:18]=[O:4])=[CH:16][C:15]([CH3:20])=[CH:14][N:21]=1Komponenten
4
Reaktionsbedingungen
- Temperatur
- 75 °C
Versuchsvorschrift
Dimethylformamide (19.34 g, 0.264 moles) was added to a well stirred and cooled material of diphosgene (36.64 g, 0.185 moles) at 10° C. in 30 minutes in an ice bath followed by N-benzyl-N-(1-Propenyl)acetamide (5 g, 0.026 moles) at the same temperature. The reaction mixture was further continued for 2 hours at 30° C. The ice cold both was removed and heated to 75° C. for 8 hours. Work up procedure was carried out according to the procedure of example 1. Before that excess DMF was removed under reduced pressure. The obtained residue was subjected to chromatographic purification on silica gel to give 2-chloro-5-methylpyridine-3-carbaldehyde (3.78 g) in 92% yield.