Potassium Hydroxide → 4,5-Dichloro-2-[(4-methoxyphenyl)methyl]pyridazin-3-one

HRID 1608653Notes

Reaction equation

HRID 1608653 reaction equation
[Cl:1][C:2]1[C:3](=[O:9])[NH:4][N:5]=[CH:6][C:7]=1[Cl:8].[K].[OH-].[K+].[CH3:13][O:14][C:15]1[CH:22]=[CH:21][C:18]([CH2:19]Cl)=[CH:17][CH:16]=1>CO.C1(C)C=CC=CC=1.[Br-].C([N+](CCCC)(CCCC)CCCC)CCC.C(OCC)(=O)C>[Cl:1][C:2]1[C:3](=[O:9])[N:4]([CH2:19][C:18]2[CH:21]=[CH:22][C:15]([O:14][CH3:13])=[CH:16][CH:17]=2)[N:5]=[CH:6][C:7]=1[Cl:8]

Participants

9

Reactant 4

HCID 14797Potassium HydroxideHCID 699934-Methyloxybenzyl chlorideHCID 732474,5-Dichloro-3-hydroxypyridazineHCID 5462222Potassium

Product 1

HCID 165783544,5-Dichloro-2-[(4-methoxyphenyl)methyl]pyridazin-3-oneYield 41%

Reagents, catalysts & solvents 4

HCID 74236Tetrabutylammonium BromideCatalystHCID 887MethanolSolventHCID 1140TolueneSolvent2×HCID 8857Ethyl AcetateSolvent

Procedure

1.65 g (10 mmoles) of 4,5-dichloro-3(2H)-pyridazinone are converted into potassium salt with an equimolar amount of potassium hydroxide dissolved in methanol, and the methanol is removed in vacuo. To the suspension of the salt in 30 ml of toluene a solution of 1.56 g (10 mmoles) of 4-methoxybenzyl chloride in 30 ml of toluene is dropped under stirring, then 0.6 g (1.8 mmole) of tetrabutyl ammonium bromide is added. The reaction mixture is boiled for 3 hours under reflux cooling and evaporated to dryness in vacuo. The residue is dissolved in water, then the solution is extracted with ethyl acetate, dried and evaporated. The crude product thus obtained is optionally subjected to column chromatography on a silica gel column using ethyl acetate as solvent. Thus 1.17 g (41% ) of the desired compound are obtained. M.p.: 117°-120° C.

Workup

  1. customthe methanol is removed in vacuo
  2. additionis dropped
  3. temperatureunder reflux
  4. temperaturecooling
  5. customevaporated to dryness in vacuo
  6. dissolutionThe residue is dissolved in water
  7. extractionthe solution is extracted with ethyl acetate
  8. customdried
  9. customevaporated
  10. customThe crude product thus obtained

Sources & evidence

ORD record
ord-b2bae42bc95a47faa5c39af890f815dd
Source dataset
uspto-grants-1995_03
Patent number
US05395934

Reaction notes

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