Synthesis
GENERAL METHOD: To a solution of p-bromobenzaldehyde (3.6 mmol) in glacial acetic acid (4 mL) was added nitroethane (7.2 mmol) followed by cyclohexylamine (3.6 mmol, 0.4 mL). The reaction mixture was placed in a microwave reactor and heated at 120 °C for 30 min. After completion of the reaction, it was cooled to room temperature, water (10 mL) was added to the reaction mixture and left to precipitate the product. The precipitated (E)-1-bromo-4-(2-nitroprop-1-en-1-yl)benzene was collected by filtration. The filtrate was further diluted with water (20 mL) and extracted with dichloromethane (3 x 10 mL). The organic phases were combined and washed with saturated aqueous NaHCO3 (3 x 10 mL). The organic layer was dried over anhydrous Na2SO4, filtered and concentrated in vacuum to remove the solvent to obtain the crude product. The crude product was purified by silica gel fast column chromatography (eluent: dichloromethane/hexane) and finally recrystallized with ethanol to obtain pure (E)-1-bromo-4-(2-nitroprop-1-en-1-yl)benzene.
References
[1] Tetrahedron, 2008, vol. 64, # 27, p. 6294 - 6299
[2] Tetrahedron Letters, 1986, vol. 27, # 33, p. 3843 - 3844
[3] Chemical Communications, 2016, vol. 52, # 65, p. 10060 - 10063
[4] Medicinal Chemistry, 2018, vol. 14, # 2, p. 181 - 199
[5] Patent: US6303816, 2001, B1
