1 H NMR ( 400 . 1 MHz , CDCl 3 ) δ 1 . 71 - 1 . 82 ( 2 H , m ) , 1 . 84 - 2 . 02 ( 2 H , m ) , 3 . 25 - 3 . 43 ( 2 H , m ) , 3 . 48 - 3 . 66 ( 1 H , m ) , 4 . 03 - 4 . 19 ( 2 H , m ) , 5 . 15 ( 2 H , s ) , 7 . 27 - 7 . 39 ( 6 H , m ) , 7 . 79 - 7 . 82 ( 1 H , m ) , 8 . 37 - 8 . 40 ( 1 H , m ) , 8 . 69 ( 1 H , d ) ; m / z = 313 [ M + H ] +.