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

HRID 2415671Notes

Reaction equation

HRID 2415671 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): δ 12.41 (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-7aea32cdf3f44fe28822c5dfac0356a4
Source dataset
uspto-grants-2004_11
Patent number
US06821973B2

Reaction notes

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