1 H NMR ( 399 . 9 MHz , DMSO - d 6 ) δ 1 . 72 - 1 . 75 ( 2 H , m ) , 2 . 23 - 2 . 30 ( 2 H , m ) , 3 . 39 - 3 . 45 ( 2 H , m ) , 4 . 39 - 4 . 43 ( 2 H , m ) , 7 . 51 - 7 . 63 ( 4 H , m ) , 7 . 72 ( 1 H , d ) , 8 . 30 ( 1 H , d ) , 8 . 04 ( s ) & 8 . 71 ( s ) ( 1 H ) ; m / z = 389 [ M + H ] +.