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

HRID 1764638

Reaction equation

HRID 1764638 reaction equation
[Br: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>[Br: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 24408BromineHCID 6891086-(4-Bromophenyl)-4,5-dihydropyridazin-3(2H)-one

Product 1

HCID 6890736-(4-Bromophenyl)-2,3-dihydropyridazin-3-one

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent2×

Procedure

An 86.3 g. sample of 6-(p-bromophenyl)-4,5-dihydro-3(2H)-pyridazinone (prepared as in U.S. Pat. No. 3,689,652, Example 4) is dissolved in 500 ml. of glacial acetic acid by heating to 80° C. with continuous stirring. A solution of 60 g. of bromine in 80 ml. of acetic acid is added dropwise at 75°-80° C. over a one hour period. A solid is separated near the end of the addition. The reaction mixture is heated with stirring on the steam bath for half an hour more, then is poured into 3 liters of cracked ice-water. The white solid formed is collected by filtration and is air dried. The product is then recrystallized from ethyl alcohol to afford 6-(p-bromophenyl)-3(2H)-pyridazinone.

Workup

  1. dissolution3,689,652, Example 4) is dissolved in 500 ml
  2. customA solid is separated near the end of the addition
  3. temperatureThe reaction mixture is heated
  4. additionis poured into 3 liters of cracked ice-water
  5. customThe white solid formed
  6. filtrationis collected by filtration
  7. customdried
  8. customThe product is then recrystallized from ethyl alcohol

Sources & evidence

ORD record
ord-649f26b9064f4a15b6199354e375f8ed
Source dataset
uspto-grants-1978_09
Patent number
US04117130

Linked notes

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