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

HRID 1764643Notes

Reaction equation

HRID 1764643 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 24408BromineHCID 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×

Conditions

Temperature
65 °C

Procedure

A 47.5 g. portion of 6-(p-chlorophenyl)-4,5-dihydro-3(2H)-pyridazinone (prepared as in Example 1 of U.S. Pat. No. 3,689,652) is dissolved in 250 ml. of glacial acetic acid at 65°-70° C. with stirring. Then a solution of 14 ml. (42 g.) of bromine liquid in 50 ml. of acetic acid is added portionwise during a 20 minute period. The reaction mixture is stirred at 65° C. for 3 hours and is cooled to 4° C. The precipitate is collected and washed with 100 ml. of ethyl acetate. The solid is suspended in 500 ml. of water, 25 ml. of concentrated ammonium hydroxide is added and the mixture is stirred at room temperature overnight. The precipitate is collected, washed with 500 ml. of water and dried at 60° C. to afford 6-(p-chlorophenyl)-3(2H)-pyridazinone.

Workup

  1. dissolution3,689,652) is dissolved in 250 ml
  2. temperatureis cooled to 4° C
  3. customThe precipitate is collected
  4. washwashed with 100 ml
  5. additionof concentrated ammonium hydroxide is added
  6. stirringthe mixture is stirred at room temperature overnight
  7. customThe precipitate is collected
  8. washwashed with 500 ml
  9. dry with materialof water and dried at 60° C.

Sources & evidence

ORD record
ord-e1e73ca2d1a44e1082493c68a08bd6fd
Source dataset
uspto-grants-1978_09
Patent number
US04117130

Reaction notes

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