1 H NMR ( Varian 400 MHz , DMSO - d 6 ) : δ 9 . 7 ( s , 1 H ) , 6 . 8 - 7 . 5 ( m , 14 H ) , 4 . 2 ( m , 1 H ) , 3 . 9 ( m , 1 H ) , 3 . 7 ( t , J = 6 . 8 Hz , 2 H ) , 3 . 4 ( m , 1 H ) , 3 . 3 ( s , 3 H ) , 2 . 5 ( d , J = 8 . 0 Hz , 2 H ) , 1 . 8 ( m , 2 H ) , 1 . 4 ( d , J = 6 . 8 Hz , 6 H ) , 1 . 5 ( m , 1 H )