1 H NMR ( 300 MHz , CDCl 3 ) δ 1 . 62 - 2 . 19 ( 6 H , m ) , 2 . 67 - 2 . 79 ( 4 H , m ) , 3 . 21 - 3 . 33 ( 2 H , m ) , 3 . 35 - 3 . 49 ( 2 H , m ) , 3 . 77 - 3 . 97 ( 3 H , m ) , 7 . 04 ( 2 H , d , J = 8 . 3 Hz ) , 7 . 13 ( 1 H , s ) , 7 . 21 - 7 . 25 ( 2 H , m ) , 7 . 27 - 7 . 32 ( 4 H , m ) .