Dimethylformamide → ethyl 3-benzyloxy-1-phenyl-1H-pyrazole-4-carboxylate

HRID 2221607Notes

Reaction equation

[OH:1][C:2]1[C:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[CH:5][N:4]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[N:3]=1.[CH2:18](Br)[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1.C(=O)([O-])[O-].[K+].[K+].CN(C)C=O>O>[CH2:18]([O:1][C:2]1[C:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[CH:5][N:4]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[N:3]=1)[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1

Participants

Conditions

Temperature: 50 °C

Procedure

A mixture of ethyl 3-hydroxy-1-phenyl-1H-pyrazole-4-carboxylate (7.76 g), benzyl bromide (3.97 mL), potassium carbonate (6.91 g) and N,N-dimethylformamide (75 mL) was stirred overnight at 50° C. The reaction mixture was poured into water and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed successively with dilute hydrochloric acid and saturated brine, dried over anhydrous magnesium sulfate and concentrated. The residue was subjected to silica gel column chromatography to give ethyl 3-benzyloxy-1-phenyl-1H-pyrazole-4-carboxylate (8.29 g, yield 77%) as colorless crystals from a fraction eluted with ethyl acetate-hexane (1:1, v/v). The crystals were recrystallized from ethyl acetate-hexane. melting point: 113-114° C.

Workup

extractionthe mixture was extracted with ethyl acetate
washThe ethyl acetate layer was washed successively with dilute hydrochloric acid and saturated brine
dry with materialdried over anhydrous magnesium sulfate
concentrationconcentrated

Sources & evidence

ORD record: ord-74190dc192f349919183fae15c78455a
Source dataset: uspto-grants-2008_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07368578B2

Reaction notes

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