1: [2,5-dichloro-4-(diethoxyphosphorylmethyl)benzyl]phosphonic acid diethyl ester With sodium hydride in tetrahydrofuran Heating; 2: [4-isopropylphenyl]methanone in tetrahydrofuran Wittig-Horner reaction; 0.5 h; Heating;

1: [2,5-dichloro-4-(diethoxyphosphorylmethyl)benzyl]phosphonic acid diethyl ester With sodium hydride in tetrahydrofuran T=40°C; Horner reaction; 2: benzaldehyde in tetrahydrofuran T=40°C; 1.5 h; Further stages.;