1: isocyano-acetic acid ethyl ester With potassium tert-butylate in tetrahydrofuran T=-25°C; 0.25 h; Inert atmosphere; 2: ethoxycarbonyl isothiocyanate in tetrahydrofuran T=-25 - 0°C; 0.833333 h; Inert atmosphere;

1: ammonium hydroxide / ethanol; water / 40 °C / Reflux 2: potassium tert-butylate / N,N-dimethyl acetamide / 1 h / 100 °C / Inert atmosphere 3: N-ethyl-N,N-diisopropylamine; trichlorophosphate / 30 h / Reflux; Inert atmosphere View Scheme