Iodine → 2,2-Dimethylchroman-6-carboxylic acid

HRID 1417707Notes

Reaction equation

HRID 1417707 reaction equation
[C:1]([C:4]1[CH:5]=[C:6]2[C:11](=[CH:12][CH:13]=1)[O:10][C:9]([CH3:15])([CH3:14])[CH2:8][CH2:7]2)(=[O:3])C.[OH-].[Na+].[O-]Cl.[Na+].[O-:21]S([O-])=O.[Na+].[Na+].II.OS(O)(=O)=O>O1CCOCC1.C(Cl)(Cl)(Cl)Cl>[CH3:14][C:9]1([CH3:15])[CH2:8][CH2:7][C:6]2[C:11](=[CH:12][CH:13]=[C:4]([C:1]([OH:3])=[O:21])[CH:5]=2)[O:10]1

Participants

9

Reactant 6

HCID 807IodineHCID 1118Sulfuric AcidHCID 14798Sodium HydroxideHCID 24437Sodium SulfiteHCID 1820772,2-Dimethyl-6-acetylchroman2×HCID 23665760Sodium Hypochlorite

Product 1

HCID 2220642,2-Dimethylchroman-6-carboxylic acidYield 92%

Reagents, catalysts & solvents 2

HCID 5943Carbon TetrachlorideSolventHCID 312751,4-DioxaneSolvent

Conditions

Temperature
65 °C

Procedure

A solution of 6-acetyl-2,2-dimethylchroman (Compound 215, 2.15 g, 10.5 mmol) and NaOH (2.0 g, 50 mmol) in dioxane (50 mL) and bleach (50 mL, 5.25% NaOCl) was heated at 65° C. for 4 days. Upon cooling to room temperature Na2SO3 was added until an aliquot of this solution remained colorless color when treated with of one drop of a solution of I2 in CCl4. The solution was acidified with H2SO4 (pH 4) and extracted with ether. The combined organic layers were dried (Na2SO4) and concentrated under reduced pressure. Column chromatography (EtOAc:hexanes 1:3) afforded 1.98 g (92%) of 2,2-dimethylchroman-6-carboxylic acid as a light tan solid. 1H NMR δ 7.78 (2H, m), 6.82 (1H, d, J=8.3 Hz), 2.83 (2H, t, J=6.7, Hz), 1.85 (2H, t, J=6.7 Hz), 1.37 (6H, s).

Workup

  1. additionwas added until an aliquot of this solution
  2. extractionextracted with ether
  3. dry with materialThe combined organic layers were dried (Na2SO4)
  4. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-900f71be1d9041cb9f29a768febb982e
Source dataset
uspto-grants-1999_03
Patent number
US05877207

Reaction notes

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