Methanol → Methyl 4-methyl-3-nitrobenzoate

HRID 1987354Notes

Reaction equation

HRID 1987354 reaction equation
[CH3:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[N+:11]([O-:13])=[O:12].S(=O)(=O)(O)O.[CH3:19]O>>[CH3:19][O:7][C:6](=[O:8])[C:5]1[CH:9]=[CH:10][C:2]([CH3:1])=[C:3]([N+:11]([O-:13])=[O:12])[CH:4]=1

Participants

4

Reactant 3

HCID 887MethanolHCID 1118Sulfuric AcidHCID 73194-Methyl-3-nitrobenzoic acid

Product 1

HCID 81816Methyl 4-methyl-3-nitrobenzoateYield 97%

Procedure

To a solution of 4-methyl-3-nitrobenzoic acid (5.52 g, 30.5 mmol) in MeOH (100 mL) was added 98% sulfuric acid (2 mL) and the resultant mixture was refluxed overnight, then cooled to room temperature. The mixture was concentrated and the residue was dissolved in CH2Cl2 (50 mL) and water (20 mL). Solid Na2CO3 was added until the aqueous phase was basic to litmus paper. The phases were separated and the aqueous phase was extracted with CH2Cl2 (5×20 mL). The combined organic extracts were dried (Na2SO4) and concentrated and provided 5.79 g (97%) of 4-methyl-3-nitrobenzoic acid methyl ester as a white solid. To a solution of 4-methyl-3-nitrobenzoic acid methyl ester (5.01 g, 25.7 mmol) in CCl4 (65 mL) was added N-bromosuccinimide (5.04 g, 28.3 mmol) followed by 1,1′-azobis(cyclohexanecarbonitrile) (1.21 g, 4.96 mmol). The resultant mixture was refluxed for 24 hours then cooled to room temperature, filtered through filter paper, and concentrated. Purification of the crude material by column chromatography on silica gel (9:1 :hexanes-EtOAc) provided 4.30 g (61%) of 4-bromomethyl-3-nitrobenzoic acid methyl ester as a yellow oil. 1H NMR (CDCl3) δ 3.98 (s, 3H), 4.85 (s, 2H), 7.67 (d, 1H, J=7.8 Hz), 8.25 (d, 1H, J=7.8, 1.5 Hz), 8.66 (d, 1H, J=1.5 Hz).

Workup

  1. concentrationThe mixture was concentrated
  2. dissolutionthe residue was dissolved in CH2Cl2 (50 mL)
  3. additionSolid Na2CO3 was added until the aqueous phase
  4. customThe phases were separated
  5. extractionthe aqueous phase was extracted with CH2Cl2 (5×20 mL)
  6. dry with materialThe combined organic extracts were dried (Na2SO4)
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-5c8cc3d014ab44129525d4e2e993b457
Source dataset
uspto-grants-2009_06
Patent number
US07550484B2

Reaction notes

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