Water → 2-Benzyl-4,5-dichloro-2,3-dihydropyridazin-3-one

HRID 2224276Notes

Reaction equation

HRID 2224276 reaction equation
[Cl:1][C:2]1[C:7]([Cl:8])=[CH:6][N:5]=[N:4][C:3]=1[OH:9].C([O-])([O-])=O.[K+].[K+].[CH2:16](Br)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1.O>CN(C=O)C>[CH2:16]([N:4]1[C:3](=[O:9])[C:2]([Cl:1])=[C:7]([Cl:8])[CH:6]=[N:5]1)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1

Participants

6

Reactant 4

HCID 962WaterHCID 7498Benzyl BromideHCID 11430Potassium CarbonateHCID 178518919HCID 178518919, compound

Product 1

HCID 7224382-Benzyl-4,5-dichloro-2,3-dihydropyridazin-3-oneYield 96.4%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a stirring suspension of 4,5-dichloro-3-hydroxypyridazine (33 g, 200 mmol) in DMF (260 mL) at room temperature under argon was added K2CO3 (55 g, 400 mmol), followed by benzyl bromide (41 g, 505.8 mmol). After 16 h the reaction mixture was poured into a flask containing water (500 mL) with stirring. After 15 min stirring, the precipitated product was collected by filtration and washed thoroughly with water. The solid was dried in a vacuum oven at 50° C. for 16 h to obtain the title compound, 2-benzyl-4,5-dichloropyridazin-3(2H)-one, (49.2 g, 96%) as an off-white solid. MS [M+H]+ 255; HPLC retention time=3.02 min.

Workup

  1. additionAfter 16 h the reaction mixture was poured into a flask
  2. stirringAfter 15 min stirring
  3. filtrationthe precipitated product was collected by filtration
  4. washwashed thoroughly with water
  5. customThe solid was dried in a vacuum oven at 50° C. for 16 h

Sources & evidence

ORD record
ord-a785c87a78b743f0ae004f0277332b45
Source dataset
uspto-grants-2008_05
Patent number
US07378418B2

Reaction notes

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