1 H NMR ( 499 . 8 MHz , DMSO - d 6 ) δ 1 . 83 - 1 . 90 ( 2 H , m ) , 2 . 64 ( 2 H , t ) , 2 . 75 ( 2 H , t ) , 3 . 64 ( 2 H , s ) , 3 . 73 ( 2 H , t ) , 3 . 76 ( 2 H , t ) , 7 . 19 - 7 . 21 ( 1 H , m ) , 7 . 24 - 7 . 28 ( 3 H , m ) , 7 . 49 ( 1 H , d ) , 8 . 22 ( 1 H , d ) ; m / z = 411 [ M + H ] +.