Hydrochloric Acid → Methyl 4-hydroxy-6-methoxy-2-naphthalenecarboxylate

HRID 1067151Notes

Reaction equation

HRID 1067151 reaction equation
C([O:4][C:5]1[C:14]2[C:9](=[CH:10][CH:11]=[C:12]([O:15][CH3:16])[CH:13]=2)[CH:8]=[C:7]([C:17]([O:19][CH2:20]C)=[O:18])[CH:6]=1)(=O)C.[OH-].[Na+].Cl.OS(O)(=O)=O>O.C(O)C.CO>[OH:4][C:5]1[C:14]2[C:9](=[CH:10][CH:11]=[C:12]([O:15][CH3:16])[CH:13]=2)[CH:8]=[C:7]([C:17]([O:19][CH3:20])=[O:18])[CH:6]=1

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 1118Sulfuric AcidHCID 14798Sodium HydroxideHCID 11415005HCID 11415005, compound

Product 1

HCID 21192140Methyl 4-hydroxy-6-methoxy-2-naphthalenecarboxylateYield 68%

Reagents, catalysts & solvents 3

HCID 702EthanolSolventHCID 887MethanolSolventHCID 962WaterSolvent3×

Procedure

A solution of ethyl 4-acetoxy6-methoxy-2-naphthoate (3.0 g, 10.4 mmol) and sodium hydroxide (2.5 g, 62.5 mmol) in water (60 cm3) and ethanol (15 cm3) was maintained at 80-90° C. for 3 hours. The cooled solution was poured into water (400 cm3) and cautiously acidified with c. HCl. The resulting suspension was extracted with EtOAc (5×75 cm3). The combined extracts were dried (Na2SO4) and evaporated to give a pale brown solid. This solid was dissolved in methanol (50 cm3) containing c. H2SO4 (˜1 cm3) and was refluxed for 4 hours. The cooled mixture was diluted with water (500 cm3) and extracted with EtOAc (4×50 cm3). The combined extracts were washed with aq. sat. NaHCO3 (2×100 cm3) and water (100 cm3). Removal of the dried (Na2SO4) EtOAc gave a pale brown solid which was recrystallised from EtOAc/hexane to afford methyl 4-hydroxy-6-methoxy-2-naphthoate (yield=1.63 g, theoretical yield=2.41 g, 68%, m.p.=193-195° C. (uncorrected)).

Workup

  1. extractionThe resulting suspension was extracted with EtOAc (5×75 cm3)
  2. dry with materialThe combined extracts were dried (Na2SO4)
  3. customevaporated
  4. customto give a pale brown solid
  5. additioncontaining c
  6. extractionextracted with EtOAc (4×50 cm3)
  7. washThe combined extracts were washed with aq. sat. NaHCO3 (2×100 cm3) and water (100 cm3)
  8. customRemoval of the
  9. dry with materialdried (Na2SO4) EtOAc
  10. customgave a pale brown solid which
  11. customwas recrystallised from EtOAc/hexane

Sources & evidence

ORD record
ord-7fc1ead633a64345a442c513325ce06f
Source dataset
uspto-grants-2001_06
Patent number
US06248264B1

Reaction notes

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