1 H NMR ( 399 . 9 MHz , DMSO - d 6 ) δ 2 . 53 - 2 . 61 ( 6 H , m ) , 2 . 81 - 2 . 85 ( 2 H , m ) , 3 . 61 ( 4 H , t ) , 7 . 12 - 7 . 17 ( 2 H , m ) , 7 . 23 - 7 . 27 ( 1 H , m ) , 7 . 34 - 7 . 39 ( 1 H , m ) , 7 . 61 ( 1 H , d ) , 8 . 25 ( 1 H , d ) ; m / z = 395 [ M + H ] +.