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

HRID 1006688Notes

Reaction equation

HRID 1006688 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-1844a9ddff3f491a8e0ce433a7d926f4
Source dataset
uspto-grants-2004_09
Patent number
US06790960B2

Reaction notes

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