Hydrochloric Acid → 1-Pyrimid-2-yl-4-(4-chloro-phenyl)pyrazolin-5-one

HRID 977937Notes

Reaction equation

HRID 977937 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([CH2:8][C:9]([O:11]CC)=O)=[CH:4][CH:3]=1.[CH3:14]OC(OC)N(C)C.[NH:22]([C:24]1[N:29]=[CH:28][CH:27]=[CH:26][N:25]=1)[NH2:23].Cl.[OH-].[Na+]>C(O)C.O>[N:25]1[CH:26]=[CH:27][CH:28]=[N:29][C:24]=1[N:22]1[C:9](=[O:11])[C:8]([C:5]2[CH:4]=[CH:3][C:2]([Cl:1])=[CH:7][CH:6]=2)=[CH:14][NH:23]1

Participants

8

Reactant 5

HCID 313Hydrochloric Acid2×HCID 14798Sodium HydroxideHCID 78373Dimethylformamide dimethyl acetalHCID 84177Ethyl (4-chlorophenyl)acetateHCID 3465582-Hydrazinylpyrimidine

Product 1

HCID 135905371-Pyrimid-2-yl-4-(4-chloro-phenyl)pyrazolin-5-oneYield 26.4%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

19.9 g (0.1 mol) of ethyl 4-chloro-phenylacetate are heated with 23.8 g (0.2 mol) of dimethylformamide dimethyl acetal to 100° C. for 5 hours. All volatile components are then distilled off at this temperature in a vacuum from a water pump. The oily residue, which essentially consists of ethyl α-dimethylaminomethylene-4-chlorophenylacetate, is dissolved in 140 ml of ethanol without further purification, and 11 g (0.1 mol) of 2-hydrazinopyrimidine and 10 ml of concentrated hydrochloric acid are added. The mixture is heated under reflux for 5 hours and cooled to room temperature, and, after the addition of 9 g of concentrated sodium hydroxide solution, is stirred for 5 hours at room temperature. After it has been neutralized with dilute hydrochloric acid, the mixture is diluted with 1 l of water. The precipitated crystals are filtered off under suction, washed with water and dried in the air. 7.2 g (26.4% of theory) of 1-pyrimid-2-yl-4-(4 -chlorophenyl)-pyrazolin-5-one of melting point 190° to 191° C. (methanol) are obtained.

Workup

  1. distillationAll volatile components are then distilled off at this temperature in a vacuum from a water pump
  2. additionare added
  3. temperatureThe mixture is heated
  4. temperatureunder reflux for 5 hours
  5. filtrationThe precipitated crystals are filtered off under suction
  6. washwashed with water
  7. customdried in the air

Sources & evidence

ORD record
ord-da94d7a384214827985c0fc3aac0fdf6
Source dataset
uspto-grants-1987_05
Patent number
US04663327

Reaction notes

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