Nitrogen → 1-(4-chlorophenyl)-5-phenyl-4,5-dihydro-(1H)-pyrazole-3-carboxamidine

HRID 19759Notes

Reaction equation

HRID 19759 reaction equation
[NH4+:1].[Cl-].[N:3]#N.C[Al](C)C.[Cl:9][C:10]1[CH:15]=[CH:14][C:13]([N:16]2[CH:20]([C:21]3[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=3)[CH2:19][C:18]([C:27](OCC)=O)=[N:17]2)=[CH:12][CH:11]=1>C1(C)C=CC=CC=1.CO>[Cl:9][C:10]1[CH:15]=[CH:14][C:13]([N:16]2[CH:20]([C:21]3[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=3)[CH2:19][C:18]([C:27]([NH2:3])=[NH:1])=[N:17]2)=[CH:12][CH:11]=1

Participants

7

Reactant 4

HCID 947NitrogenHCID 25517Ammonium ChlorideHCID 16682925TrimethylaluminumHCID 23730695Ethyl 1-(4-chlorophenyl)-5-phenyl-4,5-dihydro-1H-pyrazole-3-carboxylate

Product 1

HCID 116594121-(4-chlorophenyl)-5-phenyl-4,5-dihydro-(1H)-pyrazole-3-carboxamidine

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 1140TolueneSolvent3×

Procedure

Part A: A stirred suspension of NH4Cl (2.68 g, 0.05 mol) in toluene (25 ml) is cooled to 0° C. in an N2 atmosphere. A solution of Me3Al in toluene (25 ml of a 2 M solution) is slowly added and the mixture is allowed to attain room temperature. A solution of ethyl 1-(4-chlorophenyl)-5-phenyl-4,5-dihydro-(1H)-pyrazole-3-carboxylate (3.29 gram, 10 mmol) in toluene (25 ml) is slowly added and the reaction mixture is stirred at 80° C. for 16 hours. After cooling to 0° C. methanol is slowly added and the formed precipitate is removed by filtration. The filtrate is concentrated and the residue is dissolved in a mixture of dichloromethane and methanol. The formed precipitate is removed by filtration. The filtrate is concentrated and the remaining residue crystallised from dichloromethane to give 1-(4-chlorophenyl)-5-phenyl-4,5-dihydro-(1H)-pyrazole-3-carboxamidine.HCl (2.70 g, 73% yield). 1H-NMR (200 MHz, DMSO-d6): 3.08 (dd, J=18 and 7 Hz, 1H), 3.82 (dd, J=18 and 13 Hz, 1H), 5.84 (dd, J=13 and 7 Hz, 1H), 7.15-7.46 (m, 9H), 8.85 (br s, 2H), 9.00 (br s, 2H).

Workup

  1. customto attain room temperature
  2. stirringthe reaction mixture is stirred at 80° C. for 16 hours
  3. additionis slowly added
  4. customthe formed precipitate is removed by filtration
  5. concentrationThe filtrate is concentrated
  6. dissolutionthe residue is dissolved in a mixture of dichloromethane and methanol
  7. customThe formed precipitate is removed by filtration
  8. concentrationThe filtrate is concentrated
  9. customthe remaining residue crystallised from dichloromethane

Sources & evidence

ORD record
ord-4632d2ea59e049f79a1e7e885a701630
Source dataset
uspto-grants-2010_06
Patent number
US07745476B2

Reaction notes

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