1 H - NMR ( CDCl 3 ; δ ppm ) : 7 . 48 - 7 . 45 ( m , 2 H ) , 6 . 99 - 6 . 96 ( m , 2 H ) , 4 . 20 ( q , J = 7 . 0 Hz , 2 H ) , 4 . 00 ( d , J = 7 . 0 Hz , 2 H ) , 2 . 48 - 2 . 39 ( m , 1 H ) , 1 . 91 - 1 . 85 ( m , 2 H ) , 1 . 70 - 1 . 58 ( m , 4 H ) , 1 . 49 ( t , J = 7 . 0 Hz , 3 H ) , 1 . 45 - 1 . 36 ( m , 2 H ) . 19 F - NMR ( δ ppm ; CDCl 3 ) : - 157 . 91 ( d , J = 7 . 3 Hz , 1 F ) , - 158 . 10 ( d , J = 7 . 0 Hz , 1 F ) .