Methyl 3-amino-4-hydroxybenzoate → 2-Mercapto-1,3-benzoxazole-5-carboxylic acid methyl ester

HRID 1692034Notes

Reaction equation

HRID 1692034 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:9]=[CH:10][C:11]=1[OH:12])[C:5]([O:7][CH3:8])=[O:6].[C:13]([S-])(=[S:17])OCC.[K+]>N1C=CC=CC=1>[S:17]=[C:13]1[NH:1][C:2]2[CH:3]=[C:4]([C:5]([O:7][CH3:8])=[O:6])[CH:9]=[CH:10][C:11]=2[O:12]1

Participants

4

Reactant 2

HCID 10815Methyl 3-amino-4-hydroxybenzoateHCID 2735045Potassium ethylxanthate

Product 1

HCID 53069482-Mercapto-1,3-benzoxazole-5-carboxylic acid methyl ester

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

Methyl 3-amino-4-hydroxybenzoate (5.09 g, 30.4 mmol) and potassium O-ethyl carbonodithioate (6.35 g, 39.6 mmol) were combined in pyridine (50 mL) and heated to reflux for two hours. The reaction mixture was cooled to ambient temperature. The mixture was filtered, washed with a 1 N aqueous hydrochloric acid solution, and dried on a vacuum filter overnight to afford the title compound. 1H NMR (300 MHz, DMSO-d6) δ ppm 3.88 (s, 3 H) 7.63 (d, J=8.48 Hz, 1 H) 7.69 (d, J=1.70 Hz, 1 H) 7.89 (dd, J=8.82, 1.70 Hz, 1 H); MS (ESI−) m/z 207.87 (M−H)−.

Workup

  1. temperatureheated
  2. temperatureto reflux for two hours
  3. filtrationThe mixture was filtered
  4. washwashed with a 1 N aqueous hydrochloric acid solution
  5. customdried on a vacuum
  6. filtrationfilter overnight

Sources & evidence

ORD record
ord-5250d357414444b398be735a5c8e8b35
Source dataset
uspto-grants-2012_04
Patent number
US08153813B2

Reaction notes

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