1-Piperazinecarboxylic acid, ethyl ester → Ethyl 4-(6-chloropyridazin-3-yl)piperazine-1-carboxylate

HRID 466561Notes

Reaction equation

HRID 466561 reaction equation
[Cl:1][C:2]1[N:3]=[N:4][C:5](Cl)=[CH:6][CH:7]=1.[N:9]1([C:15]([O:17][CH2:18][CH3:19])=[O:16])[CH2:14][CH2:13][NH:12][CH2:11][CH2:10]1.C(N(CC)CC)C>CN(C)C=O>[Cl:1][C:2]1[N:3]=[N:4][C:5]([N:12]2[CH2:11][CH2:10][N:9]([C:15]([O:17][CH2:18][CH3:19])=[O:16])[CH2:14][CH2:13]2)=[CH:6][CH:7]=1

Participants

5

Reactant 3

HCID 84311-Piperazinecarboxylic acid, ethyl esterHCID 8471TriethylamineHCID 673313,6-Dichloropyridazine

Product 1

HCID 15124600Ethyl 4-(6-chloropyridazin-3-yl)piperazine-1-carboxylate

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Conditions

Temperature
50 °C

Procedure

To a stirred solution of 7.5 parts of 3,6-dichloropyridazine in 75 parts of N,N-dimethylformamide was added dropwise a solution of 8 parts of ethyl 1-piperazinecarboxylate and 5.6 parts of N,N-diethylethanamine in 25 parts of N,N-dimethylformamide. Upon completion, the whole was stirred overnight at a temperature of about 50° C. After cooling, the reaction mixture was poured onto water and the product was extracted with trichloromethane. The organic layer was dried, filtered and evaporated. The residue was crystallized from 2-propanol, yielding 3.6 parts of ethyl 4-(6-chloro-3-pyridazinyl)-1-piperazinecarboxylate; mp. 123.8° C. (compound 208).

Workup

  1. temperatureAfter cooling
  2. additionthe reaction mixture was poured onto water
  3. extractionthe product was extracted with trichloromethane
  4. customThe organic layer was dried
  5. filtrationfiltered
  6. customevaporated
  7. customThe residue was crystallized from 2-propanol

Sources & evidence

ORD record
ord-4ef9d450694e41dcb3410179129b2f98
Source dataset
uspto-grants-1992_10
Patent number
US05157035

Reaction notes

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