Hydrogen Bromide → 7-Hydroxy-2-naphthoic acid

HRID 1640111Notes

Reaction equation

HRID 1640111 reaction equation
C[O:2][C:3]1[CH:12]=[C:11]2[C:6]([CH:7]=[CH:8][C:9]([C:13]([O:15]C)=[O:14])=[CH:10]2)=[CH:5][CH:4]=1.Br>CC(O)=O>[OH:2][C:3]1[CH:12]=[C:11]2[C:6]([CH:7]=[CH:8][C:9]([C:13]([OH:15])=[O:14])=[CH:10]2)=[CH:5][CH:4]=1

Participants

4

Reactant 2

HCID 260Hydrogen BromideHCID 10082020Methyl 7-methoxynaphthalene-2-carboxylate

Product 1

HCID 145125257-Hydroxy-2-naphthoic acidYield 99.8%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
100 °C

Procedure

A suspension of methyl 7-methoxy-2-naphthoate (37.21 g, 172 mmol) in 48% aqueous HBr (195 mL, 1.72 mol) and AcOH (190 mL) was heated at 100° C. for 4 h. The mixture gradually went into solution and then precipitated. The reaction mixture was cooled to rt, and water was added. The solid was filtered and washed with water. The solid was dissolved in 1N NaOH and washed with Et2O. The aqueous solution was acidified to pH 1 with concentrated HCl. The precipitate was filtered and washed with water, then dried under vacuum to give 7-hydroxy-2-naphthoic acid as an off-white solid (32.3 g, 99%). LCMS: (FA) ES− 187.1.

Workup

  1. customprecipitated
  2. temperatureThe reaction mixture was cooled to rt
  3. additionwater was added
  4. filtrationThe solid was filtered
  5. washwashed with water
  6. dissolutionThe solid was dissolved in 1N NaOH
  7. washwashed with Et2O
  8. filtrationThe precipitate was filtered
  9. washwashed with water
  10. customdried under vacuum

Sources & evidence

ORD record
ord-79a85e264a444954bbcdb2999b691693
Source dataset
uspto-grants-2012_02
Patent number
US08110687B2

Reaction notes

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