Sodium Hydroxide → 2,2,4,4-Tetramethyl-3,4-dihydro-2H-1-benzopyran-6-carboxylic acid

HRID 1085024Notes

Reaction equation

HRID 1085024 reaction equation
[OH-:1].[Na+].Cl[O-].[Na+].[CH3:6][C:7]1([CH3:22])[CH2:16][C:15]([CH3:18])([CH3:17])[C:14]2[C:9](=[CH:10][CH:11]=[C:12]([C:19](=[O:21])C)[CH:13]=2)[O:8]1>O.O1CCOCC1>[CH3:22][C:7]1([CH3:6])[CH2:16][C:15]([CH3:17])([CH3:18])[C:14]2[C:9](=[CH:10][CH:11]=[C:12]([C:19]([OH:21])=[O:1])[CH:13]=2)[O:8]1

Participants

6

Reactant 3

HCID 14798Sodium HydroxideHCID 156611361-(2,2,4,4-Tetramethyl-3,4-dihydro-2H-1-benzopyran-6-yl)ethan-1-one2×HCID 23665760Sodium Hypochlorite

Product 1

HCID 157287092,2,4,4-Tetramethyl-3,4-dihydro-2H-1-benzopyran-6-carboxylic acid

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 312751,4-DioxaneSolvent

Conditions

Temperature
65 °C

Procedure

A solution of 2.0 (50 mmol) of NaOH in 10 ml of water was treated with 50 ml of 10% aqueous sodium hypochlorite solution and then with a solution of 1.04 g (4.31 mmol) of 2,2,4,4-tetramethyl-6-acetylchroman (Compound 46) in 15 ml of dioxane. The mixture was heated at 65° C. for 40 hours under a nitrogen atmosphere. The mixture was cooled to room temperature and then diluted with water. The mixture was then washed with ether and the aqueous layer was treated with sodium metabisulphite until it was negative to the potassium iodide - starch test. The aqueous layer was then acidified with 10% H2SO4 and then extracted with ether. This ether extract was washed with water and saturated NaCl solution and then dried (MgSO4). Solvent was removed in-vacuo and the residue recrystallized from ethyl acetate to give the title compound as a white solid. PMR (CDCl3): & 1.39 (6H, s), 1.40 (6H, s), 1.88 (2H, s), 6.85 (1H, d, J~8.7 Hz), 7.85 (1H, dd, J~8.7 Hz, 2.1 Hz), 8.09 (1H, d, J~2.1 Hz). MS exact mass, m/e 234.1256 (calcd. for C14H18O3, 234.1256).

Workup

  1. temperatureThe mixture was cooled to room temperature
  2. washThe mixture was then washed with ether
  3. additionthe aqueous layer was treated with sodium metabisulphite until it
  4. extractionextracted with ether
  5. extractionThis ether extract
  6. washwas washed with water and saturated NaCl solution
  7. dry with materialdried (MgSO4)
  8. customSolvent was removed in-vacuo
  9. customthe residue recrystallized from ethyl acetate

Sources & evidence

ORD record
ord-09ccecf258b2495c956c4bfbca3ff42e
Source dataset
uspto-grants-1991_04
Patent number
US05006550

Reaction notes

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