Acetic Acid → 2-(Bromomethyl)-4-methoxy-1-nitrobenzene

Temperature

40 °C

3-Methyl-4-nitroanisole (41, 2.50 g, 15.0 mmol) and 1,3-dibromo-5,5-dimethylhydantoin (5.00 g, 17.5 mmol) were combined in 250 mL of C6H5Cl, and acetic acid (75 μL, 1.31 mmol) and 1,1′-azobis(cyclohexanecarbonitrile) (VAZO 88, 150 mg, mmol) were added to the stirring solution. The solution was stirred at 40° C. for 72 h. The crude reaction mixture was washed three times with hot NaHCO3 solution (75 mL, 80° C.), and once with water (75 mL). The organic portion was dried over MgSO4 to give an orange solid after filtration and solvent removal. The solid was filtered through a plug of silica gel to yield a mixture of the brominated product and unbrominated starting material that was carried on to the next step without further purification. Pure material could be obtained from flash chromotography on silica (15:3:2 hexanes/EtOAc/C6H5CH3) to give a brown oil (117 mg, 3.19%). TLC Rf=0.34 (4:1 hexanes/EtOAc). 1H NMR (CDCl3, 500 MHz) δ 3.91 (3H, s), 4.85 (2H, s), 6.92 (1H, dd, J=4.5, 15.0 Hz), 7.02 (1H, d, J=5.0 Hz), 8.13 (1H, d, , J=15.5 Hz).). 13C NMR (CDCl3, 125 MHz) δ 30.19, 56.25, 114.11, 117.69, 127.61, 128.48, 135.72, 163.45. HRMS (ESI): Calcd for MH+, 245.9766; Found 245.9760.

1. customThe crude reaction mixture
2. washwas washed three times with hot NaHCO3 solution (75 mL, 80° C.)
3. dry with materialThe organic portion was dried over MgSO4
4. customto give an orange solid
5. filtrationafter filtration and solvent removal
6. filtrationThe solid was filtered through a plug of silica gel
7. customto yield
8. additiona mixture of the brominated product
9. customwas carried on to the next step without further purification
10. customPure material could be obtained from flash chromotography on silica (15:3:2 hexanes/EtOAc/C6H5CH3)

ORD record

ord-2cbf9dca7fbd403fadfa2d5a77948fe8

Source dataset

uspto-grants-2007_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07160732B2