Phosphorus oxychloride → 3-Chloro-6-(4-cyanophenyl)pyridazine

HRID 372691Notes

Reaction equation

HRID 372691 reaction equation
[C:1]([C:3]1[CH:8]=[CH:7][C:6]([C:9]2[CH:10]=[CH:11][C:12](=O)[NH:13][N:14]=2)=[CH:5][CH:4]=1)#[N:2].P(Cl)(Cl)([Cl:18])=O>>[C:1]([C:3]1[CH:8]=[CH:7][C:6]([C:9]2[N:14]=[N:13][C:12]([Cl:18])=[CH:11][CH:10]=2)=[CH:5][CH:4]=1)#[N:2]

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 194194914-(6-Oxo-1,6-dihydropyridazin-3-yl)benzonitrile

Product 1

HCID 64052563-Chloro-6-(4-cyanophenyl)pyridazine

Procedure

A 3.42 g. portion of 6-(p-cyanophenyl)-3(2H)-pyridazinone in 25 ml. of phosphorus oxychloride is stirred and heated at reflux temperature for 3 hours. Most of the excess phosphorus oxychloride is removed under reduced pressure. Cracked ice-water is added to the concentrate which is stirred until the excess phosphorus oxychloride hydrolyzes. The solid is collected by filtration, dried and recrystallized from dimethylformamide-water, yielding 6-(p-cyanophenyl)-3-chloropyridazine, m.p. 236°-238° C.

Workup

  1. temperatureheated
  2. temperatureat reflux temperature for 3 hours
  3. customMost of the excess phosphorus oxychloride is removed under reduced pressure
  4. additionCracked ice-water is added to the
  5. concentrationconcentrate which
  6. filtrationThe solid is collected by filtration
  7. customdried
  8. customrecrystallized from dimethylformamide-water

Sources & evidence

ORD record
ord-9412ad88d33840089a40008381090d26
Source dataset
uspto-grants-1978_05
Patent number
US04092311

Reaction notes

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