Methanol → Benzoic acid, 5-chloro-2-hydroxy-, methyl ester

HRID 1681854Notes

Reaction equation

HRID 1681854 reaction equation
[Cl:1][C:2]1[CH:3]=[CH:4][C:5]([OH:11])=[C:6]([CH:10]=1)[C:7]([OH:9])=[O:8].OS(O)(=O)=O.[CH3:17]O>>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]([OH:11])=[C:6]([CH:10]=1)[C:7]([O:9][CH3:17])=[O:8]

Participants

4

Reactant 3

HCID 887MethanolHCID 1118Sulfuric Acid2×HCID 94475-Chlorosalicylic Acid

Product 1

HCID 77684Benzoic acid, 5-chloro-2-hydroxy-, methyl esterYield 94.8%

Procedure

A mixture of 5-chloro-2-hydroxybenzoic acid (100 g, 0.57 mol), 20 ml of conc. H2SO4 and 200 ml of dry methanol was heated under reflux for 22 hours. An additional 5 ml of conc. H2SO4 was then added and the solution heated for an additional 24 hours. The solvent was evaporated under reduced pressure and the resulting residue poured into aqueous saturated Na2CO3 and then extracted with CH2Cl2 (2×400 ml). The organic layers were combined, dried over anhydrous Na2SO4, and evaporated to give the desired compound as a white solid (100.5 g, 94.8% yield), mp 44°-46° C. IR (nujol) 1680 (ester) cm-1. NMR (CDCl3) δ10.60 (s, 1H, OH), 7.73 (d, 1H, JBC =3 Hz HC), 7.33 (d of d, 1H, JAB =9 Hz, HB), 6.87 (d, 1H, HA), and 3.92 (s, 3H, CH3).

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 22 hours
  3. temperaturethe solution heated for an additional 24 hours
  4. customThe solvent was evaporated under reduced pressure
  5. additionthe resulting residue poured into aqueous saturated Na2CO3
  6. extractionextracted with CH2Cl2 (2×400 ml)
  7. dry with materialdried over anhydrous Na2SO4
  8. customevaporated

Sources & evidence

ORD record
ord-835b7555ddee4e4299741c300da3a86e
Source dataset
uspto-grants-1992_12
Patent number
US05175173

Reaction notes

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