2-Methyl-3-nitrobenzoic acid → Ethyl 3-(2-methyl-3-nitrophenyl)-3-oxopropionate

HRID 2051231Notes

Reaction equation

HRID 2051231 reaction equation
[CH3:1][C:2]1[C:10]([N+:11]([O-:13])=[O:12])=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=O.C(N1C=CN=C1)(N1C=CN=C1)=O.[CH2:26]([O:28][C:29](=[O:34])[CH2:30]C(O)=O)[CH3:27]>O1CCCC1>[CH3:1][C:2]1[C:10]([N+:11]([O-:13])=[O:12])=[CH:9][CH:8]=[CH:7][C:3]=1[C:4](=[O:6])[CH2:30][C:29]([O:28][CH2:26][CH3:27])=[O:34]

Participants

5

Reactant 3

HCID 160962-Methyl-3-nitrobenzoic acidHCID 682631,1'-CarbonyldiimidazoleHCID 70615Monoethyl malonate

Product 1

HCID 15735717Ethyl 3-(2-methyl-3-nitrophenyl)-3-oxopropionateYield 76.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of 2-methyl-3-nitrobenzoic acid (10.0 g, 55.2 mmol) and carbonyldiimidazole (13.4 g, 82.8 mmol) in tetrahydrofuran (200 mL) is stirred at room temperature for 2 hours under an argon atmosphere. The magnesium salt of malonic acid monoethyl ester (47.4 g, 165 mmol) is added and the reaction mixture is heated at reflux for 18 hours. The reaction mixture is quenched with water (200 mL) and acidified to pH=1 with concentrated HCl. The product is extracted into ethyl acetate and washed with 1.0 N HCl, saturated aqueous sodium bicarbonate, and brine. The organic layer is dried over magnesium sulfate and evaporated. Recrystallization of the residue gives ethyl 2-methyl-3-nitro-β-oxobenzenepropanoate (10.6 g, 76%), mp=50-51° C.

Workup

  1. temperaturethe reaction mixture is heated
  2. temperatureat reflux for 18 hours
  3. customThe reaction mixture is quenched with water (200 mL)
  4. extractionThe product is extracted into ethyl acetate
  5. washwashed with 1.0 N HCl, saturated aqueous sodium bicarbonate, and brine
  6. dry with materialThe organic layer is dried over magnesium sulfate
  7. customevaporated
  8. customRecrystallization of the residue

Sources & evidence

ORD record
ord-5d6f5dfe10194839b1d5be722a082a39
Source dataset
uspto-grants-1991_05
Patent number
US05017604

Reaction notes

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