1 H NMR ( 399 . 9 MHz , CDCl 3 ) δ 1 . 49 ( 9 H , s ) , 1 . 64 - 1 . 74 ( 2 H , m ) , 2 . 00 - 2 . 03 ( 2 H , m ) , 2 . 86 - 3 . 00 ( 3 H , m ) , 4 . 16 - 4 . 34 ( 2 H , m ) , 7 . 06 - 7 . 10 ( 2 H , m ) , 7 . 96 ( 1 H , d ) , 8 . 31 ( 1 H , s ) , 9 . 73 ( 1 H , s ) ; m / z = 302 [ M + H ] +.