1: chloro-diphenylphosphine With diisopropylamine 2: 1-tert-Butyl-2-(methoxymethoxy)benzene With n-butyllithium in diethyl ether T=20°C; 12 h; 3: Compound 5.5; chloro(diisopropylamino)(phenyl)phosphine With hydrogenchloride; Compound 5.2 more than 3 stages;

1: 85 percent / diethyl ether / 1 h / -40 °C 2: HCl / diethyl ether / 1 h / 0 °C View Scheme