1 H NMR ( 499 . 802 MHz , DMSO ) δ 2 . 56 ( 4 H , t ) , 3 . 62 ( 4 H , t ) , 3 . 67 ( 2 H , s ) , 7 . 19 - 7 . 25 ( 2 H , m ) , 7 . 32 - 7 . 35 ( 1 H , m ) , 7 . 59 ( 1 H , d ) , 8 . 25 ( 1 H , d ) ; m / z = 443 [ M + H ] +.