1 H NMR ( 499 . 8 MHz , DMSO - d 6 ) δ 1 . 82 - 1 . 89 ( 2 H , m ) , 2 . 59 ( 2 H , t ) , 2 . 71 ( 2 H , t ) , 3 . 54 ( 2 H , s ) , 3 . 70 - 3 . 74 ( 7 H , m ) , 6 . 79 ( 2 H , d ) , 7 . 14 ( 2 H , d ) , 7 . 48 ( 1 H , d ) , 8 . 21 ( 1 H , d ) ; m / z = 407 [ M + H ] +.