Methanol → 3-Amino-2-methylbenzoic acid methyl ester

HRID 906118Notes

Reaction equation

HRID 906118 reaction equation
[NH2:1][C:2]1[C:3]([CH3:11])=[C:4]([CH:8]=[CH:9][CH:10]=1)[C:5]([OH:7])=[O:6].S(=O)(=O)(O)O.[CH3:17]O>>[NH2:1][C:2]1[C:3]([CH3:11])=[C:4]([CH:8]=[CH:9][CH:10]=1)[C:5]([O:7][CH3:17])=[O:6]

Participants

4

Reactant 3

HCID 887MethanolHCID 1118Sulfuric AcidHCID 27336993-Amino-2-methylbenzoic acid

Product 1

HCID 38010253-Amino-2-methylbenzoic acid methyl esterYield 23%

Conditions

Temperature
70 °C

Procedure

To 3-amino-2-methylbenzoic acid (500 mg, 3.3 mmol) in methanol (20 ml) was added sulfuric acid (500 μl) and heated to 70° C. for 22 h, at which point the volume was reduced by rotary evaporation. The residue was diluted with saturated sodium bicarbonate and extracted with ethyl acetate. The resultant organic layer was dried over sodium sulfate, filtered, and then concentrated to afford a tan oil (125 mg, 23%) of methyl 3-amino-2-methylbenzoate, which was used without further purification. 1H NMR (400 MHz, DMSO-d6): 6.99-6.93 (m, 1H), 6.89-6.86 (d, 1H), 6.81-6.78 (d, 1H), 5.12-5.07 (br. s, 2H), 3.78 (s, 3H), 2.16 (s, 3H). MS (EI) for C9H11NO2: 166 (MH+).

Workup

  1. customwas reduced by rotary evaporation
  2. additionThe residue was diluted with saturated sodium bicarbonate
  3. extractionextracted with ethyl acetate
  4. dry with materialThe resultant organic layer was dried over sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-8b2da97c3d364f86b3f105bd45398d6a
Source dataset
uspto-grants-2011_09
Patent number
US08012956B2

Reaction notes

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