Diethyl Oxalate → Ethyl 1,5-bis(4-methoxyphenyl)-1H-pyrazole-3-carboxylate

HRID 729172Notes

Reaction equation

HRID 729172 reaction equation
[Li].[CH3:2][O:3][C:4]1[CH:9]=[CH:8][C:7]([C:10](=O)[CH2:11][C:12](=O)[C:13]([O:15][CH2:16][CH3:17])=[O:14])=[CH:6][CH:5]=1.CC(C1C=CC(OC)=CC=1)=O.C(OC(=O)C(OCC)=O)C.C[Si](C)(C)[N-][Si](C)(C)C.[Li+].Cl.[CH3:52][O:53][C:54]1[CH:59]=[CH:58][C:57]([NH:60][NH2:61])=[CH:56][CH:55]=1>C(O)C>[CH3:52][O:53][C:54]1[CH:59]=[CH:58][C:57]([N:60]2[C:10]([C:7]3[CH:8]=[CH:9][C:4]([O:3][CH3:2])=[CH:5][CH:6]=3)=[CH:11][C:12]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[N:61]2)=[CH:56][CH:55]=1

Participants

7

Reactant 5

HCID 7268Diethyl OxalateHCID 74764'-MethoxyacetophenoneHCID 27239044-Methoxyphenylhydrazine hydrochlorideHCID 2733832Lithium HexamethyldisilazideHCID 67830640HCID 67830640, compound

Product 1

HCID 15002725Ethyl 1,5-bis(4-methoxyphenyl)-1H-pyrazole-3-carboxylateYield 91%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Ethyl 4-(4-methoxyphenyl)-2,4-dioxobutanoate lithium salt (60.0 g, 0.23 M) synthesized from 4-methoxyacetophenone and diethyloxalate employing lithium hexamethyldisilazide as base, and 4-methoxyphenylhydrazine hydrochloride (44 g, 0.25 M) were combined in ethanol (2 1) and stirred atRT for 24 hr, concentrated in vacuo and crystallized to afford ethyl 1,5-bis (4-methoxyphenyl)pyrazole-3-carboxylate as a white solid, 75 g, 91% yield; mp=97°-98° C.; MS, (m/e) 352 (M+).

Workup

  1. concentrationconcentrated in vacuo
  2. customcrystallized

Sources & evidence

ORD record
ord-5216e677dfc9417ea69eb12f9468e2ab
Source dataset
uspto-grants-1991_09
Patent number
US05051518

Reaction notes

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