Benzoyl Peroxide → (Z)-2-(2-bromo-6-fluoro-1-indanylidene)acetamide

N-Bromosuccinimide (22.57 g, 126.8 mmoles, Aldrich) and benzoyl peroxide (1.89 g, 7.8 mmoles, Aldrich) were added to a suspension of (E)-2-(6-fluoro-1-indanylidene)acetamide (21.00 g, 109.8 mmoles) in carbon tetrachloride (400 mL) and benzene (400 mL). The mixture was refluxed under a calcium chloride drying tube while shining an infrared lamp on it for two hours, after which time an orange solution formed. The heat and light were removed, and the solution was stirred at ambient temperature for 18 hours. The mixture was filtered, and the solids were washed with ethyl acetate. The washings and filtrate were combined and evaporated in vacuo. The residue was dissolved in ethyl acetate (800 mL) and washed with water (3×200 mL) and brine (200 mL), dried over sodium sulfate, filtered and evaporated in vacuo. The residue was chromatographed on silica gel eluting first with hexane: ethyl acetate (2:1) gradually increasing the polarity to hexane: ethyl acetate (1:1). The fractions containing the major spot were combined and evaporated in vacuo to give a yellow solid which was dried in a vacuum at 70° C. for 18 hours to give 1.022 g (3%) of (Z)-2-(2-bromo-6-fluoro-1-indanylidene)acetamide as a yellow solid, mp 162°-163° C. 1H-NMR (DMSO-d6): d7.19-7.85 (m, 5H), 6.46 (s, 1H), 6.32 (d, 1H, J=5.7 Hz), 3.64 (dd, 1H, J=5.6 Hz, 18.4 Hz) and 3.27 (d, 1H, J=18.5 Hz); steady-state nOe: irradiation at 6.46 d, observed 21% nOe at 7.39 d.

1. temperatureThe mixture was refluxed under a calcium chloride drying tube
2. customfor two hours
3. customafter which time an orange solution formed
4. temperatureThe heat
5. customlight were removed
6. filtrationThe mixture was filtered
7. washthe solids were washed with ethyl acetate
8. customevaporated in vacuo
9. dissolutionThe residue was dissolved in ethyl acetate (800 mL)
10. washwashed with water (3×200 mL) and brine (200 mL)
11. dry with materialdried over sodium sulfate
12. filtrationfiltered
13. customevaporated in vacuo
14. customThe residue was chromatographed on silica gel eluting first with hexane: ethyl acetate (2:1)
15. temperaturegradually increasing the polarity to hexane: ethyl acetate (1:1)
16. additionThe fractions containing the major spot
17. customevaporated in vacuo
18. customto give a yellow solid which
19. customwas dried in a vacuum at 70° C. for 18 hours

ORD record

ord-b0bee7be01a14edbb178cc8378550b31

Source dataset

uspto-grants-1998_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05719186