Isopropylamine → 3,5-Dichloro-4-(1-methylethylamino)pyridazine

HRID 1449727Notes

Reaction equation

HRID 1449727 reaction equation
[Cl:1][C:2]1[N:3]=[N:4][CH:5]=[C:6]([Cl:9])[C:7]=1Cl.[CH:10]([NH2:13])([CH3:12])[CH3:11]>C1(C)C=CC=CC=1>[Cl:1][C:2]1[N:3]=[N:4][CH:5]=[C:6]([Cl:9])[C:7]=1[NH:13][CH:10]([CH3:12])[CH3:11]

Participants

4

Reactant 2

HCID 6363IsopropylamineHCID 701113,4,5-Trichloropyridazine

Product 1

HCID 108221363,5-Dichloro-4-(1-methylethylamino)pyridazine

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A solution of 3,4,5-trichloropyridazine (9.2 g) and isopropylamine (16.5 g) in toluene (25 ml) is refluxed for 18 hr. Excess isopropylamine is removed by atmospheric distillation. The residual solution is cooled and diluted with dichloromethane and aqueous sodium hydroxide solution (5%). The phases are separated. The organic phase is washed with water and then with saline. The organic phase is dried over sodium sulfate and concentrated under reduced pressure to give a liquid which contains a mixture of isomeric products. The isomers are separated by flash chromatography on silica gel eluting with ether/hexane (30/70). The appropriate fractions are pooled and concentrated to give the desired isomer, NMR (CDCl3) 1.33, 4.59, 4.87 and 8.60δ; CMR (CDCl3) 24.2, 46.4, 117.1,139.3, 145.5 and 151.3 δ.

Workup

  1. customExcess isopropylamine is removed by atmospheric distillation
  2. temperatureThe residual solution is cooled
  3. additiondiluted with dichloromethane and aqueous sodium hydroxide solution (5%)
  4. customThe phases are separated
  5. washThe organic phase is washed with water
  6. dry with materialThe organic phase is dried over sodium sulfate
  7. concentrationconcentrated under reduced pressure
  8. customto give a liquid which
  9. additiona mixture of isomeric products
  10. customThe isomers are separated by flash chromatography on silica gel eluting with ether/hexane (30/70)
  11. concentrationconcentrated
  12. customto give the desired isomer, NMR (CDCl3) 1.33, 4.59, 4.87 and 8

Sources & evidence

ORD record
ord-9adad594ddb14b948b0d17328d8fd0ca
Source dataset
uspto-grants-1997_02
Patent number
US05599930

Reaction notes

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