1: methanephosphonic acid dimethyl ester With n-butyllithium in tetrahydrofuran T=-78°C; 0.5 h; Inert atmosphere; 2: methyl 2-(3-chlorophenoxy)acetate in tetrahydrofuran T=-78 - 20°C; 2.5 h; Inert atmosphere;

(i) aq. NH3, (ii) P2S5, benzene; Multistep reaction;