1 H NMR ( 399 . 9 MHz , DMSO - d 6 ) δ 1 . 59 ( 2 H , m ) , 1 . 91 ( 2 H , m ) , 2 . 12 ( 2 H , s ) , 2 . 75 ( 1 H , m ) , 3 . 03 ( 2 H , m ) , 3 . 61 ( 3 H , s ) , 4 . 34 ( 2 H , m ) , 7 . 35 ( 1 H , m ) , 7 . 63 ( 1 H , d ) , 7 . 70 ( 1 H , m ) , 8 . 23 ( 1 H , d ) , 8 . 48 ( 2 H , m ) ; m / z = 392 [ M + H ] +.