Hydrochloric Acid → 5-Methoxynaphthalen-2-ol

HRID 890947Notes

Reaction equation

HRID 890947 reaction equation
[CH3:1][O:2][C:3]1[C:12]2[C:7](=[CH:8][C:9]([O:13]C)=[CH:10][CH:11]=2)[CH:6]=[CH:5][CH:4]=1.Cl>ClC(Cl)C>[CH3:1][O:2][C:3]1[CH:4]=[CH:5][CH:6]=[C:7]2[C:12]=1[CH:11]=[CH:10][C:9]([OH:13])=[CH:8]2

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 2969161,6-Dimethoxynaphthalene

Product 1

HCID 149712425-Methoxynaphthalen-2-ol

Reagents, catalysts & solvents 1

HCID 63651,1-DichloroethaneSolvent

Procedure

Bromocatecholborane (4.11 g, 20.7 mmol) is added to a solution of 1,6-dimethoxynaphthalene (3.89 g, 20.7 mmol) in dichloroethane (60 mL). The resulting solution is heated to reflux for 72 hours, allowed to cool, and then poured into 1N HCl. The resulting mixture is extracted three times with CH2Cl2. The combined organic layers are dried (Na2SO4), filtered and concentrated to dryness. The product is purified by three columns (step gradient of 50–60–65%CH2Cl2 in hexanes) to give 5-methoxy-2-hydroxy naphthalene as an oil that solidifies on sitting (955 mg, 27%). 1H NMR (300 MHz, CDCl3) δ 8.17, 7.2–7.4, 7.0–7.1, 6.66, 5.08, 3.97.

Workup

  1. temperatureThe resulting solution is heated
  2. temperatureto reflux for 72 hours
  3. temperatureto cool
  4. extractionThe resulting mixture is extracted three times with CH2Cl2
  5. dry with materialThe combined organic layers are dried (Na2SO4)
  6. filtrationfiltered
  7. concentrationconcentrated to dryness
  8. customThe product is purified by three columns (step gradient of 50–60–65%CH2Cl2 in hexanes)

Sources & evidence

ORD record
ord-c4bb5d7e19fc45d3bce496e97bd17320
Source dataset
uspto-grants-2006_02
Patent number
US07001900B2

Reaction notes

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