Water → 1H-Pyrazole-1-carboxylic acid, 4,5-dihydro-5-phenyl-, ethyl ester

HRID 981176

Reaction equation

HRID 981176 reaction equation
C(N(CC)CC)C.[C:8]1([CH:14]2[NH:18][N:17]=[CH:16][CH2:15]2)[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1.Cl[C:20]([O:22][CH2:23][CH3:24])=[O:21].O>C(Cl)(Cl)Cl>[CH2:23]([O:22][C:20]([N:18]1[CH:14]([C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][CH:13]=2)[CH2:15][CH:16]=[N:17]1)=[O:21])[CH3:24]

Participants

6

Reactant 4

HCID 962WaterHCID 8471TriethylamineHCID 10928Ethyl chloroformateHCID 1208415-Phenyl-4,5-dihydro-1H-pyrazole

Product 1

HCID 30790771H-Pyrazole-1-carboxylic acid, 4,5-dihydro-5-phenyl-, ethyl esterYield 62%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

Triethylamine (2.1 g) was added to a solution of 2.92 g 5-phenyl-2-pyrazoline in 50 ml chloroform, and the mixture was stirred with ice cooling. To the resulting solution, was added dropwise 2.17 g ethyl chloroformate, and the mixture was stirred for one hour. After addition of 50 ml water, the mixture was extracted with 50 ml chloroform, the extract was dried, the dried solution was concentrated, and the residue was purified by silica gel chromatography (chloroform/methanol=100/1), giving 2.7 g (yield: 62%) of pure product as oil. NMR (DMSO-d6): 1.21 (3H, t, J=6 Hz), 2.6-3.7 (2H, m), 4.18 (2H, q, J=6 Hz), 5.22 (1H, dd, J=6, 12 Hz), 6.92 (1H, t, J=2 Hz), 7.1-7.5 (5H, m).

Workup

  1. stirringthe mixture was stirred for one hour
  2. extractionthe mixture was extracted with 50 ml chloroform
  3. customthe extract was dried
  4. concentrationthe dried solution was concentrated
  5. customthe residue was purified by silica gel chromatography (chloroform/methanol=100/1)

Sources & evidence

ORD record
ord-3bad1db943884d71a99e043437695970
Source dataset
uspto-grants-1991_02
Patent number
US04990529

Linked notes

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