1 H NMR ( 400 MHz , CDCl 3 ) δ 9 . 09 ( s , 1 H ) , 8 . 29 ( t , J = 3 . 0 Hz , 1 H ) , 8 . 06 ( d , J = 3 . 0 Hz , 1 H ) , 7 . 97 ( dd , J = 14 . 9 , 3 . 1 Hz , 1 H ) , 7 . 81 ( dt , J = 16 . 3 , 3 . 0 Hz , 2 H ) , 7 . 70 ( dd , J = 15 . 0 , 3 . 0 Hz , 1 H ) , 7 . 56 ( dd , J = 14 . 9 , 2 . 9 Hz , 1 H ) , 7 . 37 ( d , J = 15 . 0 Hz , 1 H ) , 6 . 54 ( t , J = 15 . 0 Hz , 1 H ) , 3 . 54 ( s , 2 H ) , 2 . 54 - 2 . 44 ( m , 4 H ) , 2 . 39 - 2 . 29 ( m , 7 H ) , 2 . 14 ( s , 3 H ) . LR - MS ( ESI ) m / z 508 ( M + 1 ) .