1 H NMR ( 400 MHz , CD 3 OD ) δ 8 . 24 ( dd , J = 6 . 7 , 2 . 4 Hz , 1 H ) , 8 . 05 ( d , J = 2 . 6 Hz , 1 H ) , 8 . 04 - 7 . 95 ( m , 2 H ) , 7 . 91 ( dd , J = 9 . 0 , 2 . 7 Hz , 1 H ) , 7 . 68 ( dd , J = 7 . 5 , 1 . 8 Hz , 1 H ) , 7 . 33 ( t , J = 8 . 9 Hz , 1 H ) , 7 . 28 ( d , J = 9 . 1 Hz , 1 H ) , 6 . 69 ( dd , J = 7 . 5 , 5 . 1 Hz , 1 H ) , 4 . 89 - 4 . 84 ( m , 1 H ) , 3 . 30 - 3 . 16 ( m , 4 H ) , 2 . 81 ( s , 3 H ) , 2 . 31 - 2 . 06 ( m , 4 H ) . LR - MS ( ESI ) m / z 513 ( M + 1 ) .