Ethyl diazoacetate → Diethyl 4-[(4-chloro-2-nitrophenyl)hydroxymethyl]-1H-pyrazole-3,5-dicarboxylate

HRID 428409Notes

Reaction equation

HRID 428409 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]([OH:16])[C:9]#[C:10][C:11]([O:13][CH2:14][CH3:15])=[O:12])=[C:4]([N+:17]([O-:19])=[O:18])[CH:3]=1.[N+:20](=[CH:22][C:23]([O:25][CH2:26][CH3:27])=[O:24])=[N-:21]>C(OCC)C>[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]([OH:16])[C:9]2[C:22]([C:23]([O:25][CH2:26][CH3:27])=[O:24])=[N:20][NH:21][C:10]=2[C:11]([O:13][CH2:14][CH3:15])=[O:12])=[C:4]([N+:17]([O-:19])=[O:18])[CH:3]=1

Participants

4

Reactant 2

HCID 12192Ethyl diazoacetateHCID 18358875Ethyl 4-(4-chloro-2-nitrophenyl)-4-hydroxy-2-butynoate

Product 1

HCID 18358881Diethyl 4-[(4-chloro-2-nitrophenyl)hydroxymethyl]-1H-pyrazole-3,5-dicarboxylateYield 59%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

A solution of ethyl 4-(4-chloro-2-nitrophenyl)-4-hydroxy-2-butynoate (5.00 g, 17.7 mmol) and ethyl diazoacetate (2.75 g, 26.5 mmol) in diethyl ether (43.3 mL) was refluxed for 5 days. After cooling to room temperature the reaction mixture was chromatographed eluting with ethyl acetate:hexanes (20:80, 30:70, 40:60, and 50:50). All of the fractions containing the desired compound were combined, concentrated on the rotary evaporator, and the product was recrystallized twice from toluene (total volume 225 mL) to give the title compound as a white solid (4.15 g, 59%, mp 60° C.).

Workup

  1. customwas chromatographed
  2. washeluting with ethyl acetate:hexanes (20:80, 30:70, 40:60, and 50:50)
  3. additionAll of the fractions containing the desired compound
  4. concentrationconcentrated on the rotary evaporator
  5. customthe product was recrystallized twice from toluene (total volume 225 mL)

Sources & evidence

ORD record
ord-42e6a47bb1474e8297d000619e49ffe9
Source dataset
uspto-grants-2001_11
Patent number
US06313290B1

Reaction notes

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