Hydrochloric Acid → 3-Hydroxy-4-iodonaphthalene-2-carboxylic acid

HRID 2301277Notes

Reaction equation

HRID 2301277 reaction equation
[OH-].[Na+].[I-:3].[Na+].[OH:5][C:6]1[C:7]([C:16]([OH:18])=[O:17])=[CH:8][C:9]2[C:14]([CH:15]=1)=[CH:13][CH:12]=[CH:11][CH:10]=2.Cl[O-].[Na+].S([O-])([O-])(=O)=S.[Na+].[Na+].Cl>CO>[OH:5][C:6]1[C:7]([C:16]([OH:18])=[O:17])=[CH:8][C:9]2[C:14]([C:15]=1[I:3])=[CH:13][CH:12]=[CH:11][CH:10]=2

Participants

8

Reactant 6

HCID 313Hydrochloric AcidHCID 5238Sodium IodideHCID 71043-Hydroxy-2-naphthoic acidHCID 14798Sodium HydroxideHCID 24477Sodium ThiosulfateHCID 23665760Sodium Hypochlorite

Product 1

HCID 2422513-Hydroxy-4-iodonaphthalene-2-carboxylic acidYield 75.1%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
0 °C

Procedure

A mixture of NaOH (2.12 g) in methanol (100 mL) was stirred until the solution was homogeneous. Sodium iodide (3.98 g) and 3-hydroxy-2-naphthoic acid (5.00 g) were added and allowed to stir for 30 min. The resulting suspension was cooled to 0° C. and a 5.25% (w/v) aqueous solution of sodium hypochlorite was added dropwise and stirring continued for 1 h. Saturated sodium thiosulfate (25 mL) was added and after 5 min the solution was acidified to pH 2 by addition of 6N HCl resulting in the formation of a yellow precipitate which was filtered and washed with water (50 mL). The precipitate was transferred to a round-bottomed flask, dissolved in methanol (70 mL) and toluene (100 mL), concentrated, redissolved in methanol (70 mL), concentrated, redissolved again in methanol (70 mL) and toluene (100 mL) and concentrated to afford the product as a yellow solid (6.26 g). MS m/z 313 (M−1). 1H NMR (DMSO-d6): δ12.41 (broad, 1 H), 8.63 (s, 1 H), 8.05-7.97 (m, 2 H), 7.70 (m, 1 H), 7.42 (m, 1H).

Workup

  1. stirringto stir for 30 min
  2. stirringstirring
  3. filtrationwas filtered
  4. washwashed with water (50 mL)
  5. customThe precipitate was transferred to a round-bottomed flask
  6. dissolutiondissolved in methanol (70 mL)
  7. concentrationtoluene (100 mL), concentrated
  8. dissolutionredissolved in methanol (70 mL)
  9. concentrationconcentrated
  10. dissolutionredissolved again in methanol (70 mL)
  11. concentrationtoluene (100 mL) and concentrated

Sources & evidence

ORD record
ord-1f34c3a309e441889b172a70ae9c0905
Source dataset
uspto-grants-2002_12
Patent number
US06500818B1

Reaction notes

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