Benzyl Chloride → Benzyl 2-benzyl-4-oxo-3,4-dihydropyridine-1(2H)-carboxylate

HRID 264608Notes

Reaction equation

HRID 264608 reaction equation
Cl[C:2]([O:4][CH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)=[O:3].C[O:13][C:14]1[CH:19]=[CH:18][N:17]=[CH:16][CH:15]=1.[CH2:20](Cl)[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1.[Mg]>O1CCCC1.CCOCC.Cl>[CH2:20]([CH:18]1[CH2:19][C:14](=[O:13])[CH:15]=[CH:16][N:17]1[C:2]([O:4][CH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)=[O:3])[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1

Participants

8

Reactant 4

HCID 7503Benzyl ChlorideHCID 10387Benzyl chloroformateHCID 692784-MethoxypyridineHCID 5462224Magnesium

Product 1

HCID 19035856Benzyl 2-benzyl-4-oxo-3,4-dihydropyridine-1(2H)-carboxylate

Reagents, catalysts & solvents 3

HCID 313Hydrochloric AcidSolventHCID 3283Diethyl EtherSolvent3×HCID 8028TetrahydrofuranSolvent2×

Procedure

165 ml (1.16 mol) of benzyl chloroformate are added dropwise over the course of 20 minutes to a solution of 104 g (0.95 mol) of 4-methoxypyridine in 1 l of anhydrous tetrahydrofuran at -70° under argon. The thick beige suspension is then diluted with 200 ml of anhydrous tetrahydrofuran. The Grignard reagent prepared from 460 ml (1.46 mol) of a 3 molar solution of benzyl chloride in anhydrous ether and 35.5 g (1.46 mol) of magnesium turnings in 160 ml of anhydrous ether is then added dropwise to the reaction mixture over the course of 75 minutes, maintaining the temperature at -70°. After a further 10 minutes, it is allowed to warm to room temperature. It is diluted with 500 ml of ether, 900 ml of 4N hydrochloric acid are added dropwise, and the phases are separated. The organic phases are washed with water and brine, dried over magnesium sulfate and evaporated to dryness. The residue is chromatographed on silica gel with hexane/ethyl acetate (3:1). The title compound is obtained as a colourless viscous oil. TLC: hexane/ethyl acetate (1:3) Rf =0.7, IR: 1725, 1665, 1602 cm-1.

Workup

  1. additionis then added dropwise to the reaction mixture over the course of 75 minutes
  2. temperaturemaintaining the temperature at -70°
  3. additionare added dropwise
  4. customthe phases are separated
  5. washThe organic phases are washed with water and brine
  6. dry with materialdried over magnesium sulfate
  7. customevaporated to dryness
  8. customThe residue is chromatographed on silica gel with hexane/ethyl acetate (3:1)

Sources & evidence

ORD record
ord-9a84571cc6334aacb66531aaae3e8299
Source dataset
uspto-grants-1997_07
Patent number
US05646144

Reaction notes

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