1 H NMR ( 399 . 9 MHz , DMSO - d 6 ) δ 2 . 25 - 2 . 30 ( 1 H , m ) , 2 . 33 - 2 . 42 ( 1 H , m ) , 3 . 65 - 3 . 76 ( 3 H , m ) , 3 . 89 ( 1 H , d ) , 5 . 69 - 5 . 72 ( 1 H , m ) , 6 . 82 - 6 . 84 ( 1 H , m ) , 7 . 00 - 7 . 04 ( 1 H , m ) , 7 . 29 - 7 . 32 ( 1 H , m ) , 7 . 71 - 7 . 75 ( 1 H , m ) , 8 . 21 - 8 . 24 ( 2 H , m ) ; m / z = 351 [ M + H ] +.