6-Hydroxy-2-naphthoic acid → Methyl 6-hydroxy-2-naphthoate

HRID 725697Notes

Reaction equation

HRID 725697 reaction equation
[OH:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[CH:8]=[C:7]([C:12]([OH:14])=[O:13])[CH:6]=[CH:5]2.[CH:15](Cl)(Cl)Cl.CO>CO.OS(O)(=O)=O>[OH:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[CH:8]=[C:7]([C:12]([O:14][CH3:15])=[O:13])[CH:6]=[CH:5]2

Participants

5

Reactant 2

HCID 855576-Hydroxy-2-naphthoic acidHCID 21584188Chloroform methanol

Product 1

HCID 390995Methyl 6-hydroxy-2-naphthoate

Reagents, catalysts & solvents 2

HCID 1118Sulfuric AcidCatalystHCID 887MethanolSolvent

Procedure

6-Hydroxy-2-naphthoic acid (5.0 g, 26.6 mmol) was dissolved in 125 mL of methanol and refluxed with 6 drops of conc. H2SO4 for 36 hours. TLC analysis (SiO2, 10:1 CHCl3 /MeOH) revealed only a trace of the acid left. The solution was cooled partially and concentrated to dryness on a rotary evaporator. The solid residue was dissolved in 200 mL of ether and washed successively with 100 mL of saturated aq. NaHCO3 and brine. Drying over MgSO4 and evaporating the solvent left 4.6 g of (85.5%) slightly yellow solid which showed only one spot on TLC. The material is sufficiently pure for use in subsequent reactions but may be purified further by recrystallization from ether affording a white solid mp 169°-169.5° C.; 1H NMR delta 3.976 (s, 3H), 5.3 (br. s, 1H), 7.16-8.54 (m, 6H); IR (KBr) 3370, 1680, 1630, 1435, 1310, 1210 cm-1. ##STR27##

Workup

  1. waitleft
  2. temperatureThe solution was cooled partially
  3. concentrationconcentrated to dryness on a rotary evaporator
  4. dissolutionThe solid residue was dissolved in 200 mL of ether
  5. washwashed successively with 100 mL of saturated aq. NaHCO3 and brine
  6. dry with materialDrying over MgSO4
  7. customevaporating the solvent
  8. waitleft 4.6 g of (85.5%) slightly yellow solid which
  9. custommay be purified further by recrystallization from ether affording a white solid mp 169°-169.5° C.

Sources & evidence

ORD record
ord-5cb7e0acd60048b8a110af85a8ba3165
Source dataset
uspto-grants-1998_01
Patent number
US05707559

Reaction notes

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