Phosphorus oxychloride → 1-Benzyl-7-chloro-2-methylpyrrolo[2,3-d]pyridazine

HRID 1734537Notes

Reaction equation

HRID 1734537 reaction equation
[CH2:1]([N:8]1[C:12]2[C:13](=O)[NH:14][N:15]=[CH:16][C:11]=2[CH:10]=[C:9]1[CH3:18])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.P(Cl)(Cl)([Cl:21])=O>>[CH2:1]([N:8]1[C:12]2=[C:13]([Cl:21])[N:14]=[N:15][CH:16]=[C:11]2[CH:10]=[C:9]1[CH3:18])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 194377751-Benzyl-2-methyl-6,7-dihydropyrrolo[2,3-d]pyridazine 7-one

Product 1

HCID 194377481-Benzyl-7-chloro-2-methylpyrrolo[2,3-d]pyridazineYield 84%

Conditions

Temperature
85 °C

Procedure

A suspension of 2.0 g (8.3 mmol) of 1-benzyl-2-methyl-6,7-dihydropyrrolo[2,3-d]pyridazine 7-one in 20 ml of phosphorus oxychloride is stirred at 85° C. for 7 h. The excess phosphorus oxychloride is subsequently distilled off and the residue is hydrolyzed in 50 ml of water. After neutralization with 2 N sodium hydroxide solution, the mixture is extracted with 3×50 ml of dichloromethane. The organic extracts are washed with 50 ml of water, dried over magnesium sulfate and concentrated. The residue is recrystallized from methanol. 1.8 g (84%) of the title compound are isolated. M.p.: 152°-156° C.

Workup

  1. distillationThe excess phosphorus oxychloride is subsequently distilled off
  2. extractionAfter neutralization with 2 N sodium hydroxide solution, the mixture is extracted with 3×50 ml of dichloromethane
  3. washThe organic extracts are washed with 50 ml of water
  4. dry with materialdried over magnesium sulfate
  5. concentrationconcentrated
  6. customThe residue is recrystallized from methanol

Sources & evidence

ORD record
ord-008acae3681a41fca463bfce7a87fe61
Source dataset
uspto-grants-1996_07
Patent number
US05534515

Reaction notes

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