1 H NMR ( 500 MHz , DMSO - d 6 ) δ 12 . 19 ( s br , 2 H ) , 7 . 94 ( s , 1 H ) , 7 . 42 ( dd , J = 8 . 6 , 7 . 4 Hz , 2 H ) , 7 . 22 ( d , J = 8 . 7 Hz , 2 H ) , 7 . 16 ( tt , J = 7 . 5 , 1 . 0 Hz , 1 H ) , 7 . 13 - 7 . 08 ( m , 4 H ) , 6 . 76 ( dd , J = 16 . 7 , 10 . 5 Hz , 1 H ) , 6 . 05 ( dd , J = 16 . 7 , 2 . 4 Hz , 1 H ) , 5 . 62 ( dd , J = 10 . 5 , 2 . 4 Hz , 1 H ) , 5 . 45 - 5 . 36 ( m , 3 H ) , 4 . 35 ( d , J = 12 . 3 Hz , 1 H ) , 3 . 99 ( d , J = 12 . 9 Hz , 1 H ) , 3 . 14 ( t , J = 6 . 5 Hz , 2 H ) , 2 . 97 ( t , J = 12 . 4 Hz , 1 H ) , 2 . 57 ( t , J = 11 . 8 Hz , 1 H ) , 2 . 41 ( s , 4 H ) , 1 . 88 - 1 . 76 ( m , 1 H ) , 1 . 65 - 1 . 55 ( m , 2 H ) , 1 . 01 - 0 . 87 ( m , 2 H ) .