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

HRID 1085019Notes

Reaction equation

[CH3:1][C:2]1([CH3:15])[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([C:12](=[O:14])C)[CH:10]=2)[O:5][CH2:4][CH2:3]1.[OH-].[Na+].Cl[O-].[Na+].S(S([O-])=O)([O-])(=O)=[O:22].[Na+].[Na+]>O1CCOCC1>[CH3:15][C:2]1([CH3:1])[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([C:12]([OH:14])=[O:22])[CH:10]=2)[O:5][CH2:4][CH2:3]1

Participants

Conditions

Temperature: 60 °C

Procedure

A mixture of 1.0 g (4.9 mmol) of 4,4-dimethyl-6-acetyl chroman (Compound 38), 2.0 g (50 mmol) of NaOH, 60 ml of 10% aqueous sodium hypochlorite solution and 18 ml of dioxane was heated at 60° C. with stirring for 3 hours. The reaction mixture was cooled to room temperature and then treated with sodium metabisulphite until the mixture was negative to the potassium iodide/starch test. The reaction mixture was then acidified with conc. HC1 and the resultant precipitate was collected by filtration. The residue was washed with water and dried under vacuum to give the title compound as a white solid. PMR (CDCl3): & 1.25 (6H, s), 1.81-1.90 (2H, m), 4.22-4.30 (2H, m), 6.83 (1H, d, J~8.1 Hz), 7.84 (1H, dd, J~8.1 Hz, 1.8 Hz), 8.07 (1H, d, J~1.8 Hz). MS exact mass, m/e 206.0939 (calcd. for C12H14O3, 206.0943).

Workup

temperatureThe reaction mixture was cooled to room temperature
filtrationthe resultant precipitate was collected by filtration
washThe residue was washed with water
customdried under vacuum

Sources & evidence

ORD record: ord-e0de7e3984a54f61891ab9022d46bb44
Source dataset: uspto-grants-1991_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05006550

Reaction notes

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