1 H NMR ( 499 . 802 MHz , DMSO ) δ 2 . 59 ( 4 H , t ) , 3 . 63 ( 4 H , t ) , 3 . 74 ( 2 H , s ) , 7 . 50 ( 1 H , t ) , 7 . 60 ( 1 H , d ) , 7 . 64 ( 1 H , d ) , 7 . 69 - 7 . 74 ( 1 H , m ) , 7 . 84 ( 1 H , d ) , 8 . 26 ( 1 H , d ) ; m / z = 388 [ M + H ] +.