1 H NMR ( DMSO d 6 ) δ 9 . 00 ( 1 H , br ) , 8 . 67 ( 1 H , m ) , 7 . 79 ( 2 H , br d , J = 7 . 9 Hz ) , 7 . 68 ( 1 H , d , J = 7 . 3 Hz ) , 7 . 68 - 7 . 54 ( 2 H , m ) , 4 . 48 ( 2 H , m ) , 4 . 12 ( 1 H , dd , J = 5 . 9 , 5 . 2 Hz ) , 2 . 84 ( 1 H , m ) , 2 . 66 ( 1 H , m ) , 2 . 38 - 2 . 32 ( 2 H , m ) .