1 H NMR ( 399 . 9 MHz , DMSO - d 6 ) δ 2 . 47 ( 3 H , s ) , 2 . 54 - 2 . 58 ( 4 H , m ) , 3 . 55 ( 2 H , s ) , 3 . 62 - 3 . 66 ( 4 H , m ) , 7 . 15 - 7 . 17 ( 1 H , m ) , 7 . 22 ( 1 H , s ) , 7 . 59 ( 1 H , d ) , 8 . 26 ( 1 H , d ) , 8 . 39 - 8 . 40 ( 1 H , m ) ; m / z = 378 [ M + H ] +.