1 H NMR ( 399 . 9 MHz , DMSO - d 6 ) δ 2 . 27 - 2 . 38 ( 2 H , m ) , 3 . 63 - 3 . 88 ( 4 H , m ) , 5 . 31 - 5 . 34 ( 1 H , m ) , 7 . 32 ( 1 H , d ) , 7 . 35 - 7 . 39 ( 1 H , m ) , 7 . 47 - 7 . 50 ( 1 H , m ) , 8 . 21 - 8 . 23 ( 1 H , m ) , 8 . 25 ( 1 H , d ) , 8 . 34 ( 1 H , d ) ; m / z = 351 [ M + H ] +.