1: tri-n-butylammonium phosphate, tri-n-butylamine / dimethylformamide / 0.02 h / 0 °C View Scheme

1: POCl3 / various solvent(s) / 3 h / 0 °C 2: tri-n-butylammonium phosphate, tri-n-butylamine / dimethylformamide / 0.02 h / 0 °C View Scheme

1.1: bis(tetra-n-butylammonium) hydrogen phosphate; 4,5-dicyanoimidazole / N,N-dimethyl-formamide / 6 h / 20 °C / |Inert atmosphere 1.2: |Inert atmosphere 2.1: Dowex 50W-X8 ion-exchange resin (Na+ form) / water / |Inert atmosphere View Scheme

Yield given. Multistep reaction. Yields of byproduct given. Title compound not separated from byproducts;

in water; water-d2 T=80°C; Rate constant;