1 H NMR ( 499 . 8 MHz , DMSO - d 6 ) δ 1 . 83 - 1 . 89 ( 2 H , m ) , 2 . 65 ( 2 H , t ) , 2 . 77 ( 2 H , t ) , 3 . 71 ? 3 . 79 ( 6 H , m ) , 7 . 45 - 7 . 51 ( 2 H , m ) , 7 . 53 - 7 . 59 ( 3 H , m ) , 8 . 22 ( 1 H , d ) ; m / z = 445 [ M + H ] +.