1 H NMR : 1 H NMR ( 300 MHz , CD 3 OD ) δ 8 . 46 - 8 . 40 ( m , 2 H ) , 8 . 25 - 8 . 24 ( m , 1 H ) , 8 . 10 - 8 . 06 ( m , 1 H ) , 7 . 84 - 7 . 83 ( m , 1 H ) , 6 . 64 - 6 . 63 ( m , 1 H ) , 4 . 72 ( s , 2 H ) , 4 . 70 - 4 . 63 ( m , 2 H ) , 3 . 54 - 3 . 08 ( m , 2 H ) , 1 . 62 ( t , J = 6 . 0 Hz , 3 H ) , 1 . 48 ( t , J = 9 . 0 Hz , 3 H ) .