1 H NMR ( 499 . 8 MHz , DMSO - d 6 ) δ 1 . 86 - 1 . 92 ( 2 H , m ) , 2 . 64 ( 2 H , t ) , 2 . 77 - 2 . 81 ( 2 H , m ) , 3 . 18 ( 3 H , s ) , 3 . 73 - 3 . 78 ( 6 H , m ) , 7 . 50 ( 1 H , d ) , 7 . 53 ( 1 H , d ) , 7 . 61 ( 1 H , d ) , 7 . 80 ( 1 H , d ) , 7 . 84 ( 1 H , s ) , 8 . 22 ( 1 H , d ) ; m / z = 455 [ M + H ] +.