3,6-Dichloropyridazine → HCID 19095533, compound

HRID 466563Notes

Reaction equation

HRID 466563 reaction equation
[Cl:1][C:2]1[N:3]=[N:4][C:5](Cl)=[CH:6][CH:7]=1.[N:9]1[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=1[N:15]1[CH2:20][CH2:19][NH:18][CH2:17][CH2:16]1.C(=O)([O-])O.[Na+]>C(O)C>[Cl:1][C:2]1[N:3]=[N:4][C:5]([N:18]2[CH2:19][CH2:20][N:15]([C:10]3[CH:11]=[CH:12][CH:13]=[CH:14][N:9]=3)[CH2:16][CH2:17]2)=[CH:6][CH:7]=1

Participants

5

Procedure

A mixture of 3.3 parts of 3,6-dichloropyridazine, 3.3 parts of 1-(2-pyridinyl)piperazine, 1.5 parts of sodium hydrogencarbonate and 120 parts of ethanol was stirred and refluxed over weekend. The reaction mixture was evaporated. Water was added to the residue and the product was extracted with dichloromethane. The extract was dried, filtered and evaporated. The residue was purified by column chromatography over silica gel using a mixture of trichloromethane and methanol (99:1 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from a mixture of 2-propanol and tetrahydrofuran, yielding 2.5 parts (45.3%) of 3-chloro-6-[4-(2-pyridinyl)-1-piperazinyl]pyridazine; mp. 194.7° C. (compound 213).

Workup

  1. temperaturerefluxed over weekend
  2. customThe reaction mixture was evaporated
  3. additionWater was added to the residue
  4. extractionthe product was extracted with dichloromethane
  5. customThe extract was dried
  6. filtrationfiltered
  7. customevaporated
  8. customThe residue was purified by column chromatography over silica gel using
  9. additiona mixture of trichloromethane and methanol (99:1 by volume) as eluent
  10. customThe pure fractions were collected
  11. customthe eluent was evaporated
  12. customThe residue was crystallized from a mixture of 2-propanol and tetrahydrofuran

Sources & evidence

ORD record
ord-e11a59e65a554632bcd05af77d0fc801
Source dataset
uspto-grants-1992_10
Patent number
US05157035

Reaction notes

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