1 H NMR ( 300 MHz , DMSO - d 6 ) δ 1 . 72 - 1 . 83 ( 3 H , m ) , 1 . 95 - 2 . 10 ( 1 H , m ) , 3 . 25 - 3 . 27 ( 2 H , m ) , 3 . 44 - 3 . 56 ( 2 H , m ) , 3 . 76 - 3 . 88 ( 3 H , m ) , 7 . 04 ( 2 H , d , J = 8 . 7 Hz ) , 7 . 24 - 7 . 36 ( 4 H , m ) , 7 . 47 - 7 . 53 ( 1 H , m ) , 7 . 58 - 7 . 66 ( 1 H , m ) .