An X-ray single crystal study of C-(4-methoxy-1-vinyl)-N-phenyl nitron (1) and C-(4-methoxy-1-vinyl)-N-bromphenyl nitron (2) was undertaken. The main crystal data: (1): C16H15NO2,a= 8.402(5) Åb= 5.408(3) Å,c= 14.554(7)Å, β= 93.1 (2)°,dcal.= 1.273 g/cm3,Vcal.=660.3 (2)Å3, Z= 2, Sp.gr.Pc.M= 253.32: (2):C16H14NO2Br,a= 17.586(6)Å,b= 14.543(5)Å,c= 5.632(4)Å, α=89.8(2)°, β,=90.8(2)°, γ= 98.9(2)°,dcal.= 1.554g/cm3,Vcal.= 1423.0(2)Å,Z= 4, Sp. gr. P1,M= 332.21