Ethyl 4-chloroacetoacetate → 8-Amino-3-carboethoxy-2,6-dimethylimidazo[1,2-a]pyridine

HRID 1369584Notes

Reaction equation

HRID 1369584 reaction equation
[NH2:1][C:2]1[C:7]([NH2:8])=[CH:6][C:5]([CH3:9])=[CH:4][N:3]=1.[CH2:10]([O:12][C:13](=[O:19])[CH2:14][C:15]([CH2:17]Cl)=O)[CH3:11]>C(O)C>[NH2:8][C:7]1[C:2]2[N:3]([C:14]([C:13]([O:12][CH2:10][CH3:11])=[O:19])=[C:15]([CH3:17])[N:1]=2)[CH:4]=[C:5]([CH3:9])[CH:6]=1

Participants

4

Reactant 2

HCID 69484Ethyl 4-chloroacetoacetateHCID 107018255-Methylpyridine-2,3-diamine

Product 1

HCID 226725728-Amino-3-carboethoxy-2,6-dimethylimidazo[1,2-a]pyridineYield 28%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

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%).

Workup

  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

Sources & evidence

ORD record
ord-7008207b3a3b490bae446252962ac81b
Source dataset
uspto-grants-2003_06
Patent number
US06579884B1

Reaction notes

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