tert-Butanol → 2,4,6-Tri-tert-butyl-5-hydroxybenzofuran

HRID 1900487Notes

Reaction equation

CS(O)(=O)=O.[C:6]([C:10]1[C:15]2[CH:16]=[CH:17][O:18][C:14]=2[CH:13]=[CH:12][C:11]=1[OH:19])([CH3:9])([CH3:8])[CH3:7].[C:20](O)([CH3:23])([CH3:22])[CH3:21].[OH-].[Na+]>C(Cl)(Cl)Cl>[C:20]([C:17]1[O:18][C:14]2[CH:13]=[C:12]([C:6]([CH3:9])([CH3:8])[CH3:7])[C:11]([OH:19])=[C:10]([C:6]([CH3:9])([CH3:7])[CH3:8])[C:15]=2[CH:16]=1)([CH3:23])([CH3:22])[CH3:21]

Participants

Conditions

Temperature: 0 °C

Procedure

Methanesulfonic acid (140 ml) was added dropwise, under ice cooling, to a solution consisting of 4-tert-butyl-5-hydroxybenzofuran [J. Org. Chem., 53, 4135 (1988); 35 g, 0.18 mol], tert-butyl alcohol (70 g, 0.84 mol) and chloroform (50 ml). After stirring at 0° C. for 20 min, the mixture was poured into ice water. Subsequently, the mixture was neutralized with an aqueous solution of 1N sodium hydroxide and subjected to extraction with ethyl acetate. The extracted layer was washed with a saturated aqueous solution of sodium hydrogen carbonate, dried over anhydrous magnesium sulfate, and concentrated. The concentrate was purified by silica gel chromatography (n-hexane) to afford 2,4,6-tri-tert-butyl-5-hydroxybenzofuran [10.87 g (yield, 20%)]. Also obtained, though in low yield, was 4,6-di-tert-butyl-5-hydroxybenzofuran.

Workup

extractionsubjected to extraction with ethyl acetate
washThe extracted layer was washed with a saturated aqueous solution of sodium hydrogen carbonate
dry with materialdried over anhydrous magnesium sulfate
concentrationconcentrated
customThe concentrate was purified by silica gel chromatography (n-hexane)

Sources & evidence

ORD record: ord-4e7c19b6bd7447edbd8c3d02375da07c
Source dataset: uspto-grants-1996_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05574178

Reaction notes

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