1 H NMR ( 399 . 9 MHz , DMSO - d 6 ) δ 1 . 68 - 1 . 78 ( 2 H , m ) , 2 . 09 - 2 . 12 ( 2 H , m ) , 2 . 83 - 2 . 93 ( 4 H , m ) , 3 . 15 - 3 . 24 ( 3 H , m ) , 3 . 50 - 3 . 64 ( 4 H , m ) , 4 . 40 - 4 . 44 ( 2 H , m ) , 7 . 14 ( 1 H , dd ) , 7 . 23 ( 1 H , d ) , 7 . 39 ( 1 H , d ) , 7 . 69 ( 1 H , d ) , 7 . 71 ( 1 H , s ) , 8 . 26 ( 1 H , d ) , 11 . 09 ( 1 H , s ) ; m / z = 499 [ M + H ] +.