Dimethylformamide → 2-Chloro-5-methylpyridine-3-carbaldehyde
Reaktionsgleichung
CN(C)C=[O:4].Cl[C:7]([Cl:17])(OC(=O)OC(Cl)(Cl)Cl)Cl.[CH2:18]([N:25](C=CC)C(=O)C)[C:19]1[CH:24]=C[CH:22]=[CH:21][CH:20]=1>>[Cl:17][C:7]1[C:21]([CH:22]=[O:4])=[CH:20][C:19]([CH3:24])=[CH:18][N:25]=1Komponenten
4
Versuchsvorschrift
Dimethylformamide (2.71 g, 0.037 moles) was added to a well stirred and cooled material of triphosgene (10.99 g, 0.037 moles) at 4° C. in 30 minutes in an ice bath followed by N-benzyl-N-(1-Propenyl)acetamide (1 g, 0.005 moles) at the temperature. The reaction mixture was further continued for 2 hours at 25° C. The ice cold bath was removed and heated to75° C. for 5 hours. Work up procedure was carried out according to the procedure of example 1. The obtained residue was subjected to chromatographic purification on silica gel to give 2-chloro-5-methylpyridine-3-carbaldeyde in 92% yield.