Patent ID: 6855841

Claim:
A process for the preparation of a phosphono tcompound of the formula I in which the radicals R 3 , which can be identical or different, are C 1 -C 18 -alkyl or aryl which is unsubstituted or substituted by C 1 -C 4 -alkyl, NO 2 or OC 1 -C 4 -alkyl, and X is CN, COOZ, CONR 1 R 2 or CH 2 OY, Y is H or is a radical which is readily exchangeable for H selected from the group consisting of C 1 -C 6 -alkyl, aliphatic acyl having a C 1 -C 6 aliphatic group, and benzoyl; Z is H, an alkali metal, alkaline earth metal, C 1 -C 18 -alkyl or aryl, which is unsubstituted or substituted by C 1 -C 4 -alkyl, NO 2 or OC 1 -C 4 -alkyl; R 1 and R 2 , which can be identical or different, are H or C 1 -C 4 -alkyl, in which a hexahydrotriazine derivative of the formula II is reacted with a triacyl phosphite of the formulaII P(OCOR 3 ) 3 (III) in which R 3 and X are as defined above.