1 H NMR ( 400 MHz , DMSO ) δ 8 . 33 ( d , J = 2 . 9 Hz , 1 H ) , 8 . 06 ( d , J = 3 . 1 Hz , 1 H ) , 7 . 88 ( dd , J = 14 . 9 , 2 . 9 Hz , 1 H ) , 7 . 64 ( d , J = 2 . 9 Hz , 1 H ) , 7 . 61 - 7 . 53 ( m , 2 H ) , 7 . 46 ( d , J = 3 . 1 Hz , 1 H ) , 7 . 31 ( d , J = 15 . 0 Hz , 1 H ) , 6 . 89 ( s , 2 H ) , 3 . 54 ( s , 2 H ) , 2 . 54 - 2 . 43 ( m , 4 H ) , 2 . 42 - 2 . 29 ( m , 4 H ) , 2 . 18 ( d , J = 30 . 1 Hz , 3 H ) . LR - MS ( ESI ) m / z 612 ( M + 1 ) .