1: With thionyl chloride 1 h; Reflux; 2: With ammonia in tetrahydrofuran; water T=0 - 20°C; 2 h;

1.1: trichlorophosphate / 4 h / 120 °C 2.1: diisopropylamine; n-butyllithium / hexane; tetrahydrofuran / 3 h / -78 °C 2.2: 0.5 h / 20 °C 2.3: 20 °C / pH 1 3.1: thionyl chloride / 1 h / Reflux 3.2: 2 h / 0 - 20 °C View Scheme