1 H NMR ( 399 . 9 MHz , DMSO - d 6 ) δ 1 . 69 - 1 . 79 ( 2 H , m ) , 2 . 09 - 2 . 13 ( 2 H , m ) , 3 . 18 - 3 . 26 ( 3 H , m ) , 4 . 40 - 4 . 43 ( 2 H , m ) , 7 . 23 ( 1 H , d ) , 7 . 37 ( 1 H , d ) , 7 . 68 ( 1 H , d ) , 7 . 72 ( 1 H , dd ) , 8 . 25 ( 1 H , d ) , 8 . 29 ( 1 H , s ) , 11 . 19 ( 1 H , s ) ; m / z = 431 [ M + H ] +.