1 H NMR ( CDCl 3 ) δ = 1 . 60 ~ 1 . 72 ( 4 H , m ) 2 . 02 - 2 . 09 ( 2 H , dt ) , 2 . 33 ( 1 H , m ) , 2 . 91 ~ 2 . 94 ( 2 H , bd ) , 3 . 48 ( 2 H , s ) , 3 . 59 ( 2 H , s ) , 3 . 92 ( 3 H , s ) , 3 . 97 ( 3 H , s ) , 6 . 64 ~ 6 . 68 ( 1 H , td ) , 6 . 89 ( 1 H , s ) , 7 . 22 ~ 7 . 33 ( 6 H , m )