1 H NMR ( 400 MHz , 클로로포름 - d ) δ 7 . 56 - 7 . 43 ( m , 2 H ) , 6 . 68 - 6 . 55 ( m , 2 H ) , 4 . 34 ( s , 2 H ) , 3 . 35 ( dd , J = 11 . 2 , 2 . 4 Hz , 2 H ) , 2 . 97 ( s , 2 H ) , 2 . 00 - 1 . 80 ( m , 4 H ) , 1 . 46 ( s , 9 H ) .