Water → 4-Amino-1-naphthoic acid

HRID 325196

Reaction equation

HRID 325196 reaction equation
[NH2:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[C:5]([C:12]#N)=[CH:4][CH:3]=1.[OH-:14].[K+].[OH2:16]>>[NH2:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[C:5]([C:12]([OH:16])=[O:14])=[CH:4][CH:3]=1

Participants

4

Procedure

4-Amino-1-naphthalenecarbonitrile (1.5 g, 8.91 mmol) was suspended in a 50% KOH solution (18 mL). The heterogeneous solution was heated at reflux for 2-3 days. Once the solution became homogeneous and TLC showed no more starting material, the deep red solution was cooled and poured over 200 mL of water. The resulting solution was then filtered and the desired product was precipitated with concentrated HCl. The resulting red crystals were filtered and the filtrate was refiltered to give pink crystals. The first fraction of crystals was treated with activated carbon to remove some of the red color. A total of 1.51 g of the desired product was obtained: m.p. 169-171° C.; 1H NMR (CD3OD) d 6.69 (1H, d, J=8.2 Hz), 7.38-7.43 (1H, m), 7.48-7.54 (1H, m), 8.03 (1H, d, J=8.5 Hz), 8.13 (1H, d, J=8.2 Hz), 9.09 (1H, d, J=8.5 Hz); 13C NMR (CD3OD) d 107.39, 114.61, 122.99, 123.92, 125.21, 127.40, 128.48, 135.04, 151.35, 171.44; HRMS Calc. for C11H7NO2, 187.0633; Found, 187.0642.

Workup

  1. temperatureThe heterogeneous solution was heated
  2. temperatureat reflux for 2-3 days
  3. temperaturethe deep red solution was cooled
  4. filtrationThe resulting solution was then filtered
  5. customthe desired product was precipitated with concentrated HCl
  6. filtrationThe resulting red crystals were filtered
  7. customto give pink crystals
  8. additionThe first fraction of crystals was treated with activated carbon
  9. customto remove some of the red color

Sources & evidence

ORD record
ord-1f0f546e29bb46139313209bc69fa374
Source dataset
uspto-grants-2001_04
Patent number
US06221865B1

Linked notes

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