METHOD OF THE SYNTHESIS OF DIALKYL HALOALKYLPHOSPHONATES AND DIALKYL HALOALKYLOXYALKYLPHOSPHONATES

摘要

The invention deals with the method of the synthesis of dialkyl haloalkylphosphonates and dialkyl haloalkyloxyalkylphosphonates via a microwave-heated Michaelis-Arbuzov reaction of trialkylphosphites with dihaloalkanes or bis(haloalkyl)ethers in a closed vessel, during which the reaction mixture, containing a dihaloalkane or bis(haloalkyl)ether and a trialkylphosphite, is heated with microwave radiation with the standard frequency (2.45 GHz) to reach a reaction temperature which is specific for each individual halogen. In the subsequent reaction of the first dihaloalkane or bis(haloalkyl)ether halogen atom with trialkyl phosphite, the desired dialkyl haloalkylphosphonate or dialkyl haloalkyloxyalkylphosphonate is formed, but the reaction of its halogen atom with the so-far present trialkylphosphite, leading to the creation of the relevant bisphosphonate, no longer takes place. In the case of an inhomogeneous reaction mixture, also the desired product in the amount of 0.1-5 molar % is added to the reaction mixture for its homogenization, which homogenizes it and thus precludes its uncontrollable overheating. The entire process of synthesis is more effective, faster, less expensive and more environmentally friendly than the methods described so far in the literature. The possibility of performing the described procedure also in a continuous-flow microwave reactor allows industrial production with minimal demands on an optimization of the reaction conditions for larger quantities, eliminates some security risks, dramatically reduces the spatial demands in production and reduces the need for the usage of large-tonnage industrial reactors.