Water → Methyl 1-(4-methylphenyl)-pyrazole-5-carboxylate

HRID 1090812Notes

Reaction equation

[C:1]1([CH3:9])[CH:6]=[CH:5][C:4]([NH:7][NH2:8])=[CH:3][CH:2]=1.C(O[CH:13]=[CH:14][C:15](=O)[C:16]([O:18][CH3:19])=[O:17])C.O>C(O)(=O)C>[CH3:9][C:1]1[CH:6]=[CH:5][C:4]([N:7]2[C:15]([C:16]([O:18][CH3:19])=[O:17])=[CH:14][CH:13]=[N:8]2)=[CH:3][CH:2]=1.[CH3:9][C:1]1[CH:6]=[CH:5][C:4]([N:7]2[CH:13]=[CH:14][C:15]([C:16]([O:18][CH3:19])=[O:17])=[N:8]2)=[CH:3][CH:2]=1

Participants

Conditions

Temperature: 100 °C

Procedure

12.5 g of p-tolylhydrazine in 150 ml of glacial acetic acid were added to a solution of 16 g of methyl 4-ethoxy-2-oxobut-3-enoat in 100 ml of glacial acetic acid at 50° C. The mixture was stirred at 100° C. for 5 hours, poured into 1 liter of water, and extracted twice with 100 ml of ethyl acetate. The organic phase was washed with saturated NaHCO3 solution and subsequently with water, and dried. After evaporating in a water-pump vacuum, the mixture was separated by distillation in a high vacuum. 4.1 g of methyl 1-(4-methylphenyl)-pyrazole-5-carboxylate of boiling point 116°-120° C./0.01 torr (example 8) and 5.3 g of methyl 1-(4-methylphenyl)-pyrazole-3-carboxylate of boiling point 138°-142° C./0.01 torr were obtained. The compounds were characterized by 1H NMR spectroscopy.

Workup

extractionextracted twice with 100 ml of ethyl acetate
washThe organic phase was washed with saturated NaHCO3 solution and subsequently with water
customdried
customAfter evaporating in a water-pump vacuum
customthe mixture was separated by distillation in a high vacuum

Sources & evidence

ORD record: ord-1d095efa06a54182827e9a9d26190a23
Source dataset: uspto-grants-1992_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05082949

Reaction notes

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