7-Hydroxy-2-naphthalenesulfonic acid → Sodium

HRID 619785Notes

Reaction equation

HRID 619785 reaction equation
[H-].[Na+].[OH:3][C:4]1[CH:13]=[C:12]2[C:7]([CH:8]=[CH:9][C:10]([S:14]([OH:17])(=[O:16])=[O:15])=[CH:11]2)=[CH:6][CH:5]=1.[Na:18].[CH2:19](Br)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1>CN(C=O)C>[CH2:19]([O:3][C:4]1[CH:13]=[C:12]2[C:7]([CH:8]=[CH:9][C:10]([S:14]([OH:17])(=[O:15])=[O:16])=[CH:11]2)=[CH:6][CH:5]=1)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1.[Na:18]

Participants

7

Reactant 4

HCID 70897-Hydroxy-2-naphthalenesulfonic acidHCID 7498Benzyl BromideHCID 24758Sodium hydride2×HCID 5360545Sodium

Product 2

HCID 5360545SodiumHCID 218458607-Benzyloxynaphthalene-2-sulfonic acid

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

A 60% dispersion of sodium hydride (0.37 g, 9.22 mmol) in mineral oil is washed with hexanes twice and suspended in 40 mL of DMF. To this mixture is added slowly via an addition funnel 7-hydroxynaphthalene-2-sulfonic acid, sodium salt (1.25 g, 5.08 mmol) in 25 mL of DMF at room temperature. The reaction mixture is stirred for 2 hours during which time mild bubbling is observed (H2 evolution). The mixture is treated with benzyl bromide (1.5 mL, 12.6 mmol) and stirred for 18 hours at room temperature. Ice is added to decompose the excess NaH and the resultant mixture is concentrated in vacuo. The residue is suspended in acetone and concentrated in vacuo two times and then is dried under high vacuum. The solid is suspended in acetone, filtered and dried to yield the crude 7-benzyloxynaphthalene-2-sulfonic acid, sodium salt as a beige solid. A mixture of the sulfonic acid, sodium salt (2.47 g) in 8 mL of thionyl chloride is heated at 80° C. for 4 hours. A drop of DMF is added with vigorous bubbling resulting and the mixture is heated for an additional 30 minutes. The mixture is allowed to cool to room temperature and concentrated in vacuo. The residue is diluted in EtOAc and washed successively with water (2×), saturated NaHCO3 solution and saturated NaCl. The organic layer is dried over anhydrous MgSO4, filtered and concentrated to yield the title compound as a beige solid (1.26 g, 3.78 mmol). The crude product is of sufficient purity to be used in subsequent reactions.

Workup

  1. custommild bubbling
  2. stirringstirred for 18 hours at room temperature
  3. additionIce is added
  4. concentrationthe resultant mixture is concentrated in vacuo
  5. concentrationconcentrated in vacuo two times
  6. customis dried under high vacuum
  7. filtrationfiltered
  8. customdried

Sources & evidence

ORD record
ord-8f8f08f1b4bf45c4b85cc91f809212db
Source dataset
uspto-grants-1999_09
Patent number
US05958918

Reaction notes

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