1 H NMR ( 399 . 9 MHz , DMSO - d 6 ) δ 1 . 76 ( 2 H , m ) , 2 . 12 ( 2 H , m ) , 3 . 54 ( 2 H , m ) , 3 . 99 ( 2 H , m ) , 4 . 82 ( 1 H , m ) , 7 . 10 ( 2 H , m ) , 7 . 66 ( 1 H , d ) , 7 . 90 ( 2 H , m ) , 8 . 26 ( 1 H , d ) , 12 . 60 ( 1 H , s ) ; m / z = 408 [ M + H ] +.