1 H NMR ( 300 MHz , DMSO - d 6 ) δ 3 . 41 - 3 . 51 ( 2 H , m ) , 4 . 57 - 4 . 65 ( 2 H , m ) , 7 . 00 - 7 . 12 ( 4 H , m ) , 7 . 15 - 7 . 24 ( 1 H , m ) , 7 . 38 - 7 . 48 ( 2 H , m ) , 7 . 60 ( 2 H , d , J = 8 . 7 Hz ) , 7 . 84 ( 1 H , dd , J = 8 . 3 , 3 . 0 Hz ) , 8 . 04 - 8 . 14 ( 1 H , m ) .