1 H NMR ( 300 MHz , CDCl 3 ) δ 1 . 47 - 1 . 76 ( m , 4 H ) , 1 . 89 - 1 . 99 ( m , 4 H ) , 2 . 20 ( s , 3 H ) , 2 . 27 ( m , 2 H ) , 2 . 43 ( m , 1 H ) , 2 . 77 ( m , 2 H ) , 4 . 51 ( m , 2 H ) , 6 . 95 ( m , 1 H ) , 7 . 22 - 7 . 40 ( m , 4 H ) , 7 . 56 ( dd , 1 H , J = 7 . 8 , 4 . 9 Hz ) , 7 . 63 ( d , 1 H , J = 9 . 0 Hz ) , 8 . 16 ( m , 1 H ) , 8 . 30 ( dd , 1 H , J = 9 . 1 , 2 . 1 Hz ) , 8 . 75 ( d , 1 H , J = 2 . 0 Hz ) , 8 . 83 ( m , 1 H ) , 9 . 06 ( d , 1 H , J = 1 . 9 Hz ) ; MS ( m / e , M +): 498 ( M +), 481 , 231 , 70 .