Citric Acid → benzyl 4-oxo-2-phenyl-3,4-dihydropyridine-1(2H)-carboxylate

HRID 1436906Notes

Reaction equation

HRID 1436906 reaction equation
C[O:2][C:3]1[CH:8]=[CH:7][N:6]=[CH:5][CH:4]=1.[C:9]1([Mg]Br)[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1.O1CCCC1.Cl[C:23]([O:25][CH2:26][C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1)=[O:24].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>O1CCCC1>[CH2:26]([O:25][C:23]([N:6]1[CH:7]=[CH:8][C:3](=[O:2])[CH2:4][CH:5]1[C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)=[O:24])[C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1

Participants

6

Reactant 4

HCID 311Citric AcidHCID 10387Benzyl chloroformateHCID 692784-MethoxypyridineHCID 178420626HCID 178420626, compound

Product 1

HCID 10267212benzyl 4-oxo-2-phenyl-3,4-dihydropyridine-1(2H)-carboxylate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

In 40 ml of tetrahydrofuran was dissolved 5.46 g of 4-methoxypyridine, and added dropwise thereto was 55 ml of a 1M phenylmagnesiumbromide-tetrahydrofuran solution under nitrogen atmosphere at −60° C. of below. Subsequently, added dropwise thereto was a solution of 10.24 g of benzyl chloroformate in 50 ml of tetrahydrofuran, and the mixture was stirred for 3 hours. The temperature of the mixture was raised to room temperature, and 120 ml of a 5% aqueous citric acid solution was added thereto. The mixture was extracted with ethyl acetate and washed with saturated brine. The organic layer was dried and concentrated. To the residue was added diisopropyl ether and the precipitates were collected by filtration, to give 8.51 g of 1-benzyloxycarbonyl-4-oxo-2-phenyl-3,4-dihydro-2H-pyridine.

Workup

  1. additionadded dropwise
  2. customat −60° C.
  3. additionSubsequently, added dropwise
  4. extractionThe mixture was extracted with ethyl acetate
  5. washwashed with saturated brine
  6. customThe organic layer was dried
  7. concentrationconcentrated
  8. additionTo the residue was added diisopropyl ether
  9. filtrationthe precipitates were collected by filtration

Sources & evidence

ORD record
ord-cc79dcc24efe4b5bb4a07d5e281a2fe8
Source dataset
uspto-grants-2009_11
Patent number
US07619092B2

Reaction notes

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