反应详情

A stirred mixture of 2,3-diamino-5-methyl-pyridine (4.0 g, 32.5 mmol) and (5.9 g, 36.0 mmol) of ethyl-chloroacetoacetate in 75 ml abs. ethanol was refluxed over night. The ethanol was evaporated under reduced pressure. The residue was dissolved in 2 M HCl and washed 3 times with diethyl ether, pH was adjusted to 9 and extracted 3 times with dichloromethane. The organic layer was dried over anhydrous sodium sulfate and evaporated. The residue was purified by column chromatography on silica gel with dichloromethane:methanol 95:5 as eluent to give the title product 2.0 g (28%).

1. customThe ethanol was evaporated under reduced pressure
2. dissolutionThe residue was dissolved in 2 M HCl
3. washwashed 3 times with diethyl ether, pH
4. extractionextracted 3 times with dichloromethane
5. dry with materialThe organic layer was dried over anhydrous sodium sulfate
6. customevaporated
7. customThe residue was purified by column chromatography on silica gel with dichloromethane:methanol 95:5 as eluent