反应详情

温度

75 °C

Dimethylformamide (13.54 g, 0.185 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 25° C. The ice cold bath was removed and heated to 75° C. for 5 hours. The orange-yellow coloured organic mass was poured in ice cold water (200 g) with stirring. The mass was extracted with methylenechloride (2×200 ml) and the layer separated. The organic layer was dried over sodium sulfate, and solvent removed under reduced pressure. Residue obtained was subjected to chromatographic purification on silica gel to give 2-chloro-5-methylpyridine-3-carbaldehyde (3.78 g) in 92% yield.

1. customThe ice cold bath was removed
2. additionThe orange-yellow coloured organic mass was poured in ice cold water (200 g)
3. stirringwith stirring
4. extractionThe mass was extracted with methylenechloride (2×200 ml)
5. customthe layer separated
6. dry with materialThe organic layer was dried over sodium sulfate, and solvent
7. customremoved under reduced pressure
8. customResidue obtained
9. customwas subjected to chromatographic purification on silica gel