1 H NMR ( 300 MHz , DMSO - d 6 ) δ : 8 . 05 ( d , J = 7 . 7 Hz , 1 H ) , 7 . 84 - 7 . 73 ( m , 5 H ) , 7 . 60 ( t , J = 7 . 6 Hz , 1 H ) , 7 . 46 ( t , J = 7 . 7 Hz , 1 H ) , 6 . 59 ( d , J = 8 . 0 Hz , 1 H ) , 3 . 59 ( t , J = 7 . 6 Hz , 2 H ) , 1 . 44 - 1 . 37 ( m , 1 H ) , 1 . 26 - 1 . 18 ( m , 2 H ) , 0 . 72 ( d , J = 6 . 6 Hz , 6 H ) .