Hydrochloric Acid → 2,3-Diaminobenzoic acid methyl ester

HRID 382349Notes

Reaction equation

HRID 382349 reaction equation
[NH2:1][C:2]1[C:10]([NH2:11])=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].Cl.[C:13](=O)([O-])O.[Na+]>CO.O>[NH2:1][C:2]1[C:10]([NH2:11])=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]([O:6][CH3:13])=[O:5]

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 1980692,3-Diaminobenzoic acidHCID 516892Sodium Bicarbonate

Product 1

HCID 5718252,3-Diaminobenzoic acid methyl ester

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

A solution of 2,3-diaminobenzoic acid (0.2 g, 1.32 mmol) in methanol (40 ml) was saturated with hydrogen chloride as described above, and the mixture was subsequently heated under reflux for 2 hours. The solid residue obtained on evaporation of the solvent was dissolved in water, and the solution was adjusted to pH 7.0 with sodium hydrogen carbonate. After extraction with ethyl acetate (2×30 ml), the combined organic layers were dried (MgSO4), and the solvent was removed to give methyl 2,3-diaminobenzoate as a brown oil which solidified on trituration with petrol (40/60) (121.6 mg, 56%), m.p. 62-63° C. Found: C, 58.35; H, 5.80; N, 16.69. C8H10N2O2 requires C, 57.83; H, 6.02; N, 16.87%; δH (d6-DMSO), 200 MHz) 3.87 (3H, s, OCH3). 4.90 (2H, br s, Ar-2-NH2), 6.32 (2H, br s, Ar-3-NH2), 6.46-6.54 (1H, t, Ar-5H), 6.80-6.84 (1H, dd, Ar-4H), 7.18-7.23 (1H, dd, Ar-6H); m/z (EI) 166 (M+), 134, 106, 79.

Workup

  1. temperaturewas subsequently heated
  2. temperatureunder reflux for 2 hours
  3. customThe solid residue obtained on evaporation of the solvent
  4. extractionAfter extraction with ethyl acetate (2×30 ml)
  5. dry with materialthe combined organic layers were dried (MgSO4)
  6. customthe solvent was removed

Sources & evidence

ORD record
ord-e006568db07d4b75b33af7a2c9b06b18
Source dataset
uspto-grants-2001_10
Patent number
US06310082B1

Reaction notes

Loading…