Potassium Carbonate → 4-(4-BROMOPHENYL)-2-BUTANONE

A mixture of 2,4-pentanedione (200 mg, 206 μL, 2 mmol), the 4-bromobenzyl bromide (2 mmol), and anhydrous potassium carbonate (276 mg, 2 mmol) in methanol (10 mL) was heated at reflux temperature for 16 h. The mixture was then cooled to room temperature, methanol was removed under reduced pressure, and the resulting residue was partitioned between ethyl acetate (10 mL) and water (10 mL). The organic layer was separated, and the aqueous layer was extracted further with ethyl acetate (3×10 mL). The combined organic phase was washed with water (10 mL), dried over anhydrous Na2SO4, and then the solvent was removed under pressure. The resulting oil was chromatographed on a silica gel column using hexanes-ethyl acetate as mobile phase to give 4-(4-bromophenyl)-2-butanone as a clear liquid (302 mg, 67%): Rf=0.38 (hexanes-ethyl acetate 3:1 v/v); 1H NMR (400 MHz, CDCl3): δ 2.15 (s, 3H), 2.75 (t, J=7.2 Hz, 2H), 2.86 (t, J=7.2 Hz, 2H), 7.07 (d, J=8 Hz, 2H), 7.40 (d, J=8.4 Hz, 21; 13C NMR (100 MHz, CDCl3): δ 29.2, 30.2, 44.9, 120.0, 130.2, 131.7, 140.2, 207.4; HRMS (ESI) Calcd. for C10H11BrONa: 248.9891 [M+Na+]. Found: 248.9880.

1. temperatureat reflux temperature for 16 h
2. custommethanol was removed under reduced pressure
3. customthe resulting residue was partitioned between ethyl acetate (10 mL) and water (10 mL)
4. customThe organic layer was separated
5. extractionthe aqueous layer was extracted further with ethyl acetate (3×10 mL)
6. washThe combined organic phase was washed with water (10 mL)
7. dry with materialdried over anhydrous Na2SO4
8. customthe solvent was removed under pressure
9. customThe resulting oil was chromatographed on a silica gel column

ORD record

ord-d3658ac7205542eba4e2d16ef5a94d74

Source dataset

uspto-grants-2011_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07943650B2