1 H NMR ( 300 . 132 MHz , DMSO - d 6 ) δ 2 . 24 - 2 . 32 ( 4 H , m ) , 3 . 18 ( 2 H , s ) , 3 . 35 - 3 . 49 ( 4 H , m ) , 4 . 79 ( 2 H , s ) , 6 . 36 ( 2 H , d ) , 6 . 79 ( 2 H , d ) , 7 . 41 ( 1 H , d ) , 8 . 07 ( 1 H , d ) ; m / z = 378 [ M + H ] +.