1 H NMR ( 399 . 9 MHz , DMSO - d 6 ) δ 1 . 75 ( 2 H , m ) , 2 . 08 ( 2 H , m ) , 3 . 56 ( 2 H , m ) , 3 . 99 ( 2 H , m ) , 4 . 60 ( 1 H , m ) , 5 . 10 ( 2 H , s ) , 7 . 00 ( 4 H , m ) , 7 . 44 ( 5 H , m ) , 7 . 69 ( 1 H , d ) , 8 . 30 ( 1 H , d ) ; m / z = 470 [ M + H ] +.