1 H NMR ( 400 MHz , 메탄올 - d 4 ) δ 8 . 74 ( d , J = 2 . 1 Hz , 1 H ) , 8 . 65 ( dd , J = 2 . 2 , 0 . 4 Hz , 1 H ) , 8 . 53 ( s , 1 H ) , 7 . 98 ( dd , J = 5 . 1 , 0 . 5 Hz , 1 H ) , 7 . 83 ( d , J = 0 . 5 Hz , 1 H ) , 7 . 20 ( d , J = 5 . 1 Hz , 1 H ) , 4 . 21 ( td , J = 7 . 4 , 6 . 6 , 5 . 6 Hz , 1 H ) , 4 . 17 - 4 . 09 ( m , 1 H ) , 1 . 40 ( d , J = 6 . 4 Hz , 6 H ) , 1 . 28 ( d , J = 6 . 6 Hz , 6 H ) .