1 H NMR ( 399 . 9 MHz , DMSO - d 6 ) δ 1 . 61 - 1 . 71 ( 2 H , m ) , 1 . 81 - 1 . 86 ( 2 H , m ) , 2 . 32 - 2 . 38 ( 1 H , m ) , 3 . 01 - 3 . 08 ( 2 H , m ) , 4 . 29 ( 2 H , d ) , 5 . 32 - 5 . 34 ( 2 H , m ) , 7 . 62 ( 1 H , d ) , 8 . 23 ( 1 H , d ) , 8 . 81 ( 1 H , s ) ; m / z = 330 [ M + H ] +.