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

HRID 1452344Notes

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 N 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-91082d366bfb445c8749c8a48c096836
Source dataset: uspto-grants-1997_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05606089

Reaction notes

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