METHOD FOR SYNTHESIS OF AMINOPOLYALKYLENE PHOSPHONIC ACID COMPOUNDS Russian patent published in 2010 - IPC C07F9/38 

FIELD: chemistry.

SUBSTANCE: aminopolyalkylene phosphonic acid is obtained in the presence of not more than 0.4 wt % halogen of hydrogen acid with respect to phosphorous acid, wherein all N-H groups of the amine are converted to 50% or more of the corresponding alkylene phophonic acids. Reaction of phosphorous acid (a), amine (b) and formaldehyde (c) takes place in the presence of an acid catalyst (d) with pKa ≤ 3.1, which is homogeneous with respect to the reaction medium, in the ratio: (a):(b) between 0.1:1 and 1.5:1, (c):(b) between 0.2:1 and 2:1, (c):(a) between 3:1 and 0.5:1 and (b):(d) between 40:1 and 1:5, where (a) and (c) denote number of moles, (b) denotes number of moles multiplied by number of N-H groups in the amine, (d) denotes number of moles multiplied by number of free protons in one mole of catalyst.

EFFECT: shorter duration of the single-step cycle, prevention of corrosion, achieving better environmental and economical factors.

20 cl, 64 ex, 35 tbl