1 H NMR ( 300 MHz , DMSO - d 6 ) δ 7 . 46 - 7 . 41 ( m , 1 H ) , 7 . 06 ( s , 1 H ) , 6 . 99 - 6 . 93 ( m , 4 H ) , 6 . 52 - 6 . 50 ( m , 2 H ) , 6 . 46 ( s , 2 H ) , 5 . 74 - 5 . 69 ( m , 1 H ) , 4 . 35 - 4 . 31 ( m , 1 H ) , 4 . 11 - 3 . 97 ( m , 3 H ) , 3 . 00 ( s , 3 H ) , 1 . 32 ( t , J = 6 . 9 Hz , 3 H ) .