1 H NMR ( 399 . 9 MHz , DMSO - d 6 ) δ 1 . 69 ( 2 H , m ) , 2 . 01 ( 2 H , m ) , 3 . 51 ( 2 H , m ) , 3 . 94 ( 2 H , m ) , 4 . 46 ( 1 H , m ) , 6 . 69 ( 2 H , m ) , 6 . 83 ( 2 H , m ) , 7 . 64 ( 1 H , d ) , 8 . 25 ( 1 H , d ) , 8 . 94 ( 1 H , s ) ; m / z = 380 [ M + H ] +.