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