Ethyl 2-chloroacetoacetate → Ethyl 8-(benzyloxy)-6-bromo-2-methylimidazo[1,2-a]pyridine-3-carboxylate

HRID 1844162Notes

Reaction equation

HRID 1844162 reaction equation
[CH2:1]([O:8][C:9]1[C:10]([NH2:16])=[N:11][CH:12]=[C:13]([Br:15])[CH:14]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.Cl[CH:18]([C:24]([CH3:26])=O)[C:19]([O:21][CH2:22][CH3:23])=[O:20]>C(O)C>[CH2:1]([O:8][C:9]1[C:10]2[N:11]([C:18]([C:19]([O:21][CH2:22][CH3:23])=[O:20])=[C:24]([CH3:26])[N:16]=2)[CH:12]=[C:13]([Br:15])[CH:14]=1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

4

Reactant 2

HCID 11858Ethyl 2-chloroacetoacetateHCID 206265543-(Benzyloxy)-5-bromopyridin-2-amine

Product 1

HCID 86717925Ethyl 8-(benzyloxy)-6-bromo-2-methylimidazo[1,2-a]pyridine-3-carboxylate

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Under argon, 200 g (0.72 mol) of 3-(benzyloxy)-5-bromopyridine-2-amine Example 84A, 590 g (3.58 mol) of ethyl 2-chloroacetoacetate and 436 g 3 A molecular sieve were suspended in 6 l of ethanol and boiled at reflux for 72 h. The reaction mixture was filtered off through kieselguhr and concentrated. The residue was purified by silica gel chromatography (petroleum ether:ethyl acetate 9:1, then 6:4) and the product fractions were concentrated. This gave 221 g (79% of theory) of the target compound.

Workup

  1. temperatureat reflux for 72 h
  2. filtrationThe reaction mixture was filtered off through kieselguhr
  3. concentrationconcentrated
  4. customThe residue was purified by silica gel chromatography (petroleum ether:ethyl acetate 9:1
  5. concentration6:4) and the product fractions were concentrated

Sources & evidence

ORD record
ord-cd42fde457a54507a5fd1286341c5238
Source dataset
uspto-grants-2015_02
Patent number
US08946215B2

Reaction notes

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