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

HRID 893709Notes

Reaction equation

HRID 893709 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

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) δ 10.60 (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-59afc3f25a21488f9be1e81654ec4dde
Source dataset
uspto-grants-1992_06
Patent number
US05126364

Reaction notes

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