(Aminomethyl)phosphonic acid → N-(2-nitro-4-trifluoromethyl-5-chloro-phenyl)-aminomethanephosphonic acid

Participants

Reaction Conditions

Reaction Steps

3.3 g (30 mmol) of aminomethanephosphonic acid in 120 ml of water and 120 ml of ethanol are introduced together with 3.37 g (31.8 mmol) of soda and mixed with 7.8 g (97%, 30 mmol) of 3-trifluoromethyl-4,6-dichloronitrobenzene, and it is refluxed for 4 hours at 120° C. bath temperature. After removing the ethanol in a rotary evaporator, it is extracted three times with 100 ml of ethyl acetate. The organic phase is washed with a little water. It contains starting material and is discarded. The collected aqueous phase is adjusted acidic with 4N hydrochloric acid to pH 1 and extracted three times with 100 ml of ethyl acetate each. The organic phase is washed with water, dried, filtered and concentrated by evaporation. 6.85 g (68% of theory) of N-(2-nitro-4-trifluoromethyl-5-chloro-phenyl)-aminomethanephosphonic acid of melting point 207.3° C. is obtained.

Provenance & Evidence