1 H NMR ( 300 MHz , CDCl 3 ) δ 1 . 77 - 1 . 84 ( m , 4 H ) , 1 . 99 - 2 . 12 ( m , 4 H ) , 2 . 17 ( s , 3 H ) , 2 . 45 ( m , 3 H ) , 3 . 00 ( m , 2 H ) , 3 . 89 ( s , 3 H ) , 4 . 54 ( q , 2 H , J = 7 . 1 Hz ) , 6 . 60 ( m , 1 H ) , 6 . 94 ( m , 2 H ) , 7 . 17 - 7 . 41 ( m , 7 H ) , 7 . 60 ( m , 1 H ) ; MS ( m / e , M +): 472 ( M +), 257 , 231 , 120 .