1 H NMR ( 399 . 9 MHz , DMSO - d 6 ) δ 1 . 69 - 1 . 79 ( 2 H , m ) , 1 . 93 ( 2 H , m ) , 2 . 94 - 3 . 02 ( 1 H , m ) , 3 . 11 - 3 . 17 ( 2 H , m ) , 4 . 44 ( 2 H , m ) , 7 . 41 ( 2 H , d ) , 7 . 67 ( 1 H , d ) , 7 . 89 ( 2 H , d ) , 8 . 25 ( 1 H , d ) , 12 . 79 ( 1 H , s ) ; m / z = 392 [ M + H ] +.