phosphorodiimidate in diphenylether T=250°C; 3 h;

1: With caesium carbonate; L-proline in N,N-dimethyl-formamide 0.333333 h; Inert atmosphere; 2: With copper(l) iodide; caesium carbonate in N,N-dimethyl-formamide T=120°C; 40 h; Inert atmosphere;

in N,N-dimethyl acetamide T=140°C; 5 h;