Dimethyl Sulfate → 2-(3-Bromo-4-methoxyphenyl)-1,3-dioxolane

A mixture of 2-bromo-4-(1,3-dioxolan-2-yl)phenol (3a, 2.0 g, 8.2 mmol) and oven-dried potassium carbonate (2.7 g, 20.0) in dry acetone (20 mL) was stirred for 10 min. Dimethyl sulfate (0.9 mL, 10.0 mmol) was added dropwise to the reaction mixture and the mixture was stirred at room temperature for 18 h. Excess potassium carbonate was filtered off and washed with acetone (3×10 mL). Solvent was evaporated under reduced pressure and water (25 mL) was added. The mixture was extracted with chloroform (3×100 mL) and the organic phase was dried over Na2SO4 and evaporated under reduced pressure. The residue was column chromatographed on silica gel eluting with 20% ethyl acetate in hexanes to afford compound 4b (1.9 g, 91% yield) as a colorless oil. Rf=0.51 (25% EtOAc-hexanes); 1H NMR (300 MHz, CDCl3) δ 7.63 (d, J=2.1 Hz, 1H), 7.33 (dd, J=8.4, 2.1 Hz, 1H), 6.83 (d, J=8.1 Hz, 1H), 5.68 (s, 1H), 4.02 (m, 4H), 3.84 (s, 3H); 13C NMR (75 MHz, CDCl3) δ 156.3, 131.3, 126.8, 111.3, 102.6, 65.1, 56.1.

1. stirringthe mixture was stirred at room temperature for 18 h
2. filtrationExcess potassium carbonate was filtered off
3. washwashed with acetone (3×10 mL)
4. customSolvent was evaporated under reduced pressure and water (25 mL)
5. additionwas added
6. extractionThe mixture was extracted with chloroform (3×100 mL)
7. dry with materialthe organic phase was dried over Na2SO4
8. customevaporated under reduced pressure
9. customchromatographed on silica gel eluting with 20% ethyl acetate in hexanes

ORD record

ord-cea0e914514b4a67b5b41d56f737145d

Source dataset

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08946287B2