1 H NMR ( 400 MHz , CDCl 3 ) δ 9 . 09 ( s , 1 H ) , 8 . 39 ( t , J = 2 . 9 Hz , 1 H ) , 8 . 25 ( d , J = 16 . 0 Hz , 1 H ) , 8 . 06 ( d , J = 3 . 0 Hz , 1 H ) , 7 . 93 ( dt , J = 14 . 6 , 3 . 2 Hz , 1 H ) , 7 . 74 ( dt , J = 15 . 0 , 3 . 2 Hz , 1 H ) , 7 . 64 ( d , J = 14 . 7 Hz , 1 H ) , 7 . 61 - 7 . 53 ( m , 1 H ) , 7 . 37 ( d , J = 15 . 0 Hz , 1 H ) , 3 . 54 ( s , 2 H ) , 2 . 69 - 2 . 43 ( m , 4 H ) , 2 . 41 - 2 . 30 ( m , 4 H ) , 2 . 18 ( d , J = 30 . 2 Hz , 3 H ) , 1 . 62 ( s , 2 H ) . LR - MS ( ESI ) m / z 513 ( M + 1 ) .