Nitric Acid → 8-Amino-2-naphthalenol

HRID 448159

Reaction equation

HRID 448159 reaction equation
C[C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[CH:5]=[CH:4][CH:3]=1.[N+:12]([O-])(O)=O.[OH2:16]>>[NH2:12][C:2]1[CH:3]=[CH:4][CH:5]=[C:6]2[C:11]=1[CH:10]=[C:9]([OH:16])[CH:8]=[CH:7]2

Participants

4

Reactant 3

HCID 944Nitric Acid2×HCID 962WaterHCID 70021-Methylnaphthalene

Product 1

HCID 83588-Amino-2-naphthalenolYield 43%

Conditions

Temperature
0 °C

Procedure

To 1-methylnaphthalene (8.0 g, 56 mmol) in round bottom flask at 0° C. was added nitric acid (26 mL) dropwise. (NOTE: A slow addition of nitric acid is most important to avoid the formation of the other regioisomers). After the reaction mixture was stirred for an additional 15 min at 0° C., it was poured into 65 mL of H2O. The aqueous solution was extracted with benzene twice and the combined benzene solution was washed with 10% NaOH solution, dried with Na2SO4, and concentrated. Silica gel chromatography (EtOAc:Hexanes=5:95) gave product still containing a few percentage of the other regioisomer. It was recrystallized with EtOAc/Hexanes to give 9.0 g (43%) of 1.

Workup

  1. extractionThe aqueous solution was extracted with benzene twice
  2. washthe combined benzene solution was washed with 10% NaOH solution
  3. dry with materialdried with Na2SO4
  4. concentrationconcentrated
  5. customSilica gel chromatography (EtOAc:Hexanes=5:95) gave product
  6. additionstill containing a few percentage of the other regioisomer
  7. customIt was recrystallized with EtOAc/Hexanes

Sources & evidence

ORD record
ord-5f91dae6a2a64518914e109f7d9e558a
Source dataset
uspto-grants-2013_07
Patent number
US08481581B2

Linked notes

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