1 H NMR ( 700 . 03 MHz , DMSO - d 6 ) δ 2 . 46 ( 4 H , t ) , 3 . 62 ( 4 H , t ) , 4 . 19 ( 2 H , q ) , 4 . 39 ( 1 H , s ) , 7 . 22 ( 2 H , t ) , 7 . 33 ( 4 H , t ) , 7 . 37 ( 1 H , d ) , 7 . 48 ( 4 H , d ) , 8 . 11 ( 1 H , d ) ; m / z = 453 [ M + H ] +.