Acetic Anhydride → 4-(Acetylamino)-3-methylbenzoic acid

HRID 1177804Notes

Reaction equation

HRID 1177804 reaction equation
[NH2:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[CH3:11].C(N(CC)CC)C.[C:19](OC(=O)C)(=[O:21])[CH3:20]>C(Cl)Cl>[C:19]([NH:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[CH3:11])(=[O:21])[CH3:20]

Participants

5

Reactant 3

HCID 7918Acetic AnhydrideHCID 8471TriethylamineHCID 755984-Amino-3-methylbenzoic acid

Product 1

HCID 30159484-(Acetylamino)-3-methylbenzoic acidYield 56%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a suspension of 4-amino-3-methylbenzoic acid (60 g, 0.40 mol) in methylene chloride (800 mL) was added triethylamine (121 g, 1.19 mol). The solution became clear. Then, acetic anhydride (81 g, 0.79 mol) was added and the reaction mixture was stirred for 60 h at room temperature. The solvent was evaporated. The residue was diluted with water (400 mL) and extracted with ethyl acetate (3×600 mL). The combined organic extracts were dried over magnesium sulfate, filtered and evaporated to give the title compound as a tan solid (43 g, 56% yield). 1H-NMR (d6-DMSO, 300 MHz) δ 9.36 (s, 1H), 7.77 (s, 1H), 7.10 (s, 2H), 2.27 (s, 3H), 2.10 (s, 3H). LC/MS: tR=1.22 min, 194 (MH)+.

Workup

  1. customThe solvent was evaporated
  2. additionThe residue was diluted with water (400 mL)
  3. extractionextracted with ethyl acetate (3×600 mL)
  4. dry with materialThe combined organic extracts were dried over magnesium sulfate
  5. filtrationfiltered
  6. customevaporated

Sources & evidence

ORD record
ord-7cfaf88ccf35474aace24d1c62c0b9d1
Source dataset
uspto-grants-2010_11
Patent number
US07842808B2

Reaction notes

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