反应详情

The nitrostyrene derivative (3) is then cooled to about -10°-10° C., treated with silica gel, and reduced using 1.5-4 equivalents of a boron-based reducing agent, e.g., sodium borohydride, with 2-propanol and an inert solvent, e.g., CH2Cl2, at -10°-10° C. for 20-60 minutes to produce a nitrophenylethane derivative of formula 4 (step 2). For example, 3,4-dimethoxy-β-nitrostyrene (3) is treated with 2-propanol and SiO2 in CH2Cl2 at 0°-10° C. for 20 minutes, followed by reduction with 1.5 eq NaBH4 at 5° C. for 30 minutes to yield 2-(3,4-dimethoxyphenyl)nitroethane (4).