1 H NMR ( 300 MHz , CDCl 3 ) δ 1 . 59 - 1 . 78 ( m , 4 H ) , 1 . 89 - 1 . 99 ( m , 4 H ) , 2 . 16 ( m , 3 H ) , 2 . 27 ( t , 2 H ) , 2 . 46 ( m , 1 H ) , 2 . 83 ( br - d , 2 H ) , 4 . 38 ( t , 2 H ) , 6 . 96 ( d , 1 H ) , 7 . 24 - 7 . 47 ( m , 8 H ) , 7 . 62 - 7 . 71 ( m , 2 H ) , 7 . 80 ( d , 1 H ) , 7 . 94 ( s , 1 H ) ; MS ( m / e , M +): 531 , 451 , 357 , 316 , 257 , 231