Ammonium Chloride → alpha-(1-Ethoxymethyl-5-pyrazolyl)-2,3-dichloro-4-methoxy-benzylalcohol

HRID 1721935Notes

Reaction equation

HRID 1721935 reaction equation
C([Li])CCC.[CH2:6]([O:8][CH2:9][N:10]1[CH:14]=[CH:13][CH:12]=[N:11]1)[CH3:7].[Cl:15][C:16]1[C:23]([Cl:24])=[C:22]([O:25][CH3:26])[CH:21]=[CH:20][C:17]=1[CH:18]=[O:19].[Cl-].[NH4+]>CCCCCC.O1CCCC1.O>[CH2:6]([O:8][CH2:9][N:10]1[C:14]([CH:18]([OH:19])[C:17]2[CH:20]=[CH:21][C:22]([O:25][CH3:26])=[C:23]([Cl:24])[C:16]=2[Cl:15])=[CH:13][CH:12]=[N:11]1)[CH3:7]

Participants

8

Reactant 4

HCID 25517Ammonium ChlorideHCID 130156892,3-Dichloro-4-methoxybenzaldehydeHCID 157143991-(ethoxymethyl)-1H-pyrazoleHCID 178418339Butyllithium

Product 1

HCID 14622784alpha-(1-Ethoxymethyl-5-pyrazolyl)-2,3-dichloro-4-methoxy-benzylalcoholYield 81.5%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8028TetrahydrofuranSolventHCID 8058HexaneSolvent

Procedure

4.13 ml of 1.6M n-butyl lithium in hexane are added dropwise to a tetrahydrfuran solution of 0.76 g of 1-ethoxymethylpyrazole at -60° C. under argon gas atmosphere. the mixture is stirred at -63° to -50° C. for 1 hour. A solution of 1.23 g of 2,3-dichloro-4-methoxybenzaldehyde in tetrahydrofuran is added to the mixture, and the mixture is stirred at -50° C. to room temperature for 1 hour. An aqueous saturated ammonium chloride solution and water are added to the mixture under ice-cooling and the mixture is concentrated to remove tetrahydrofuran. The residual aqueous layer is extracted with ethyl acetate and the extract is washed with water, dried and evaporated to give colorless crystals, which are then washed with isopropyl ether and dried to give 1.62 g of α-(1-ethoxymethyl-5-pyrazolyl)-2,3-dichloro-4-methoxy-benzylalcohol.

Workup

  1. stirringthe mixture is stirred at -50° C. to room temperature for 1 hour
  2. temperaturecooling
  3. concentrationthe mixture is concentrated
  4. customto remove tetrahydrofuran
  5. extractionThe residual aqueous layer is extracted with ethyl acetate
  6. washthe extract is washed with water
  7. customdried
  8. customevaporated
  9. customto give colorless crystals, which
  10. washare then washed with isopropyl ether
  11. customdried

Sources & evidence

ORD record
ord-80735a99aa4444a89e563646f5f0c8f6
Source dataset
uspto-grants-1989_08
Patent number
US04853404

Reaction notes

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