Bromine → 6-(4-Chlorophenyl)-2,3-dihydropyridazin-3-one

HRID 372695Notes

Reaction equation

HRID 372695 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH2:9][CH2:10][C:11](=[O:14])[NH:12][N:13]=2)=[CH:4][CH:3]=1.BrBr>C(O)(=O)C>[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[CH:9]=[CH:10][C:11](=[O:14])[NH:12][N:13]=2)=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 24408Bromine3×HCID 1209906-(4-Chlorophenyl)-4,5-Dihydropyridazin-3(2H)-One

Product 1

HCID 6890856-(4-Chlorophenyl)-2,3-dihydropyridazin-3-one

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent2×

Procedure

A 283 g. portion of 6-(p-chlorophenyl)-4,5-dihydro-3(2H)-pyridazinone (prepared as described in Example 1 of U.S. Pat. No. 3,689,652) is suspended in 2500 ml. of acetic acid at room temperature with stirring. A 227 g. (72.7 ml.) portion of bromine is dissolved in 300 ml. of acetic acid and 20% of this solution is added to the reaction mixture which is then heated on a steam bath until the bromine color disappears. The balance of the bromine solution is added portionwise, over a 1/2 hour period to the heated solution. The reaction mixture is heated for an additional hour and then poured into crushed ice. The resulting solid is recovered by filtration, washed with water and dried yielding an off-white solid, m.p. 269°-272° C., 6-(p-chlorophenyl)-3(2H)-pyridazinone.

Workup

  1. temperatureThe reaction mixture is heated for an additional hour
  2. additionpoured
  3. custominto crushed ice
  4. filtrationThe resulting solid is recovered by filtration
  5. washwashed with water
  6. customdried

Sources & evidence

ORD record
ord-863ad707d98c4ca9b0b4fdd9bb46a829
Source dataset
uspto-grants-1978_05
Patent number
US04092311

Reaction notes

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