Acetic Acid → 2-bromo-5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophen-4-one

Temperature

-5 °C

To a solution of 5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophen-4-one (4.96 g, 29.8 mmol) in water (23.0 mL, 1200 mmol) and acetic acid (23.0 mL, 4000 mmol) at −5° C. was added a solution of bromine (1.6 mL, 31 mmol) in acetic acid (3.2 mL, 56 mmol) dropwise and the reaction mixture was stirred at −5° C. for 1 hr. The reaction mixture was quenched into aqueous sodium acetate, ethyl acetate (30 mL) was added, the organic layer was separated, and the aqueous layer was extracted with ethyl acetate (3×10 mL). The combined organic layers were washed with brine, dried over MgSO4, filtered, concentrated and dried under high vacuum to afford 7.3 g product as a brownish solid (99.0% yield). LCMS: (FA) ES+ , 246. 1H NMR (300 MHz, CDCl3) δ: 7.35-7.36 (br s, 1H), 2.98-3.0 (m, 2H), 2.68-2.73 (m, 2H), 1.85-2.0 (m, 4H).

1. customThe reaction mixture was quenched into aqueous sodium acetate, ethyl acetate (30 mL)
2. additionwas added
3. customthe organic layer was separated
4. extractionthe aqueous layer was extracted with ethyl acetate (3×10 mL)
5. washThe combined organic layers were washed with brine
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated
9. customdried under high vacuum

ORD record

ord-4b38777dee3642629be5597e695e65ea

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08765746B2