Salicylaldehyde → p-Toluenesulfonate

HRID 1809810Notes

Reaction equation

HRID 1809810 reaction equation
[OH:1][C:2]1[CH:9]=[CH:8][CH:7]=[CH:6][C:3]=1[CH:4]=[O:5].C(=O)([O-])[O-].[K+].[K+].[CH3:16][O:17][CH2:18][CH2:19][CH2:20][O:21][S:22]([C:25]1[CH:30]=[CH:29][C:28]([CH3:31])=[CH:27][CH:26]=1)(=[O:24])=[O:23]>CN(C=O)C>[CH3:16][O:17][CH2:18][CH2:19][CH2:20][O:1][C:2]1[CH:9]=[CH:8][CH:7]=[CH:6][C:3]=1[CH:4]=[O:5].[S:22]([C:25]1[CH:30]=[CH:29][C:28]([CH3:31])=[CH:27][CH:26]=1)([O-:24])(=[O:23])=[O:21]

Participants

6

Reactant 3

HCID 6998SalicylaldehydeHCID 11430Potassium CarbonateHCID 135229883-Methoxypropyl 4-methylbenzenesulfonate

Product 2

HCID 85570p-ToluenesulfonateYield 50%HCID 17606904HCID 17606904, compound

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A solution of 2-hydroxy-benzaldehyde (1.5 g, 12.16 mmol), potassium carbonate (8.4 g, 60.8 mmol) and toluene-4-sulfonic acid 3-methoxy-propyl ester (14.85 g, 60.8 mmol) in DMF (30 mL) is stirred at 50° C. for 3 h. The solvent is concentrated under reduced pressure, H2O is added, and the aqueous layer extracted twice with ethyl acetate. The combined organic extracts are dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue is purified by flash column chromatography on silica gel (hexane/EtOAc 4/1 to 1/2) to afford the title compound together with 50% of remaining tosylate: MS 195.0 [M+H]. Rt (HPLC, Nucleosil C18, 10:90-100:0 CH3CN/H2O+0.1% TFA within 5 min, then 100% CH3CN+0.1% TFA): 5.08 min. The mixture is further used as is in the next step.

Workup

  1. concentrationThe solvent is concentrated under reduced pressure, H2O
  2. additionis added
  3. extractionthe aqueous layer extracted twice with ethyl acetate
  4. dry with materialThe combined organic extracts are dried over anhydrous sodium sulfate
  5. concentrationconcentrated under reduced pressure
  6. customThe residue is purified by flash column chromatography on silica gel (hexane/EtOAc 4/1 to 1/2)

Sources & evidence

ORD record
ord-69278af4b13d46808a6788a4f620e290
Source dataset
uspto-grants-2013_01
Patent number
US08362040B2

Reaction notes

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