Notes - sym-Triazinetriphosphonic Acid Esters

Asymmetrically Substituted s-Triazine Phosphonates by One-Step Synthesis

Asymmetrically substituted s-triazine phosphonates with up to three different phosphonate groups C3 N3 RR'R" with R, R', R"=PO(OR"') and R"'=for example, methyl, ethyl, isopropyl or n-butyl are interesting as polymer additives like flame retardants. Typically, these compounds are obtained by multiple synthesis steps. However, this leads to high production costs, which are a disadvantage for commercial use. Here we report the one-step synthesis of mixtures of asymmetrical s-triazine phosphonates which is an easy way to adjust the thermal behaviour and other properties such as viscosities of the compounds. The synthesis is based on a Michaelis-Arbuzov reaction. A complete conversion of the reactants to the target compounds is observed which was proofed by detailed 1 H, 13 C and 31 P NMR investigations and elemental analysis. The thermal behaviour was compared with thermogravimetric analysis (TGA).

catena-Poly[oxidanium [tris{μ-[amino(iminio)methyl]phosphonato}zincate(II)]]

The crystal structure of the anionic zinc–[amino(iminio)methyl]phosphonate one-dimensional coordination polymer, Zn-AIMP, is reported; the negative charge is balanced by an oxidanium cation (H3O+) to give the composition {(H3O)[Zn(CH4N2PO3)3]} n . The building unit of the coordination polymer comprises a divalent Zn2+ cation (site symmetry \overline3..) and three [amino(iminio)methyl]phosphonate mono-anionic ligands (point group symmetry m). The AIMP ligand exists in a zwitterionic form with a total charge −1 as the phosphonate is fully deprotonated (–PO3 2−), while the amino(iminio)methyl moiety is protonated (H2N—C—NH2 +).

Insight into the Synthesis and Characterization of Organophosphorus-Based Bridged Triazine Compounds

In this article, we report the synthesis of 2,4,6-substituted s-triazine-based organophosphorus compounds via a two-step process, which enables their production in high yields, and with a high purity as solids. In the first step, a Michaelis–Arbuzov rearrangement of cyanuric chloride with triethyl phosphite afforded 2,4,6-trisdiethoxyphosphinyl-1,3,5-triazine (HEPT). Subsequently, the nucleophilic substitution reaction on the triazine carbon was achieved, owing to the electron-withdrawing ability of the phosphonate groups. This characteristic of HEPT facilitated its derivatization with bi-functional amines, producing novel P–C containing bridged triazine organophosphorus compounds. The molecular structures of all of the compounds were confirmed by NMR spectroscopy, CHN elemental analysis, and single crystal X-ray analysis. In the thermogravimetric analysis in an N₂ environment, >33% char formation was observed for the bridged compounds. The chemical composition analysis of the char obtained under the oxidative thermal decomposition of the bridged compounds confirmed the presence of phosphorus- and nitrogen-enriched species, which indicate their function in the condensed phase. Comparatively, the detection of HPO and H–C≡P in the gas phase during the pyrolysis of the bridged compounds can act as a source for PO^•, which is known for its gas phase flame inhibition reactions. The synergy of significant char formation and the generation of intermediates leading to PO^• during pyrolysis makes these molecules promising flame-retardant additives.

An efficient microwave-assisted synthesis and biological properties of polysubstituted pyrimidinyl- and 1,3,5-triazinylphosphonic acids

Polysubstituted pyrimidinylphosphonic and 1,3,5-triazinylphosphonic acids with potential biological properties were prepared in high yields by the microwave-assisted Michaelis-Arbuzov reaction of trialkyl phosphite with the corresponding halopyrimidines and halo-1,3,5-triazines, respectively, followed by the standard deprotection of the phosphonate group using TMSBr in acetonitrile. 4,6-Diamino-5-chloropyrimidin-2-ylphosphonic acid (7a) was found to exhibit a weak to moderate anti-influenza activity (28-50 μM) and may represent a novel hit for further SAR studies and antiviral improvement.