Abstract:

Diphenylamine and phosphorus trichloride interacted on each other at slow-elevated temperatures and then the brown solution obtained was treated with H₂O, followed by oxidization to produce a phosphinic acid, viz, 10-hydroxy-5,10-dihydrophenophosphazine-10-oxide(yield 45%) which could be converted to a methyl phosphinate in yield 70% by reacting with SOCl₂ and then with MeONa in MeOH. After being treated with NaH in anhydrous DMF and then heating the reaction mixture to 120 ℃, the methyl phosphinate obtained above could also be transformed into N-methyl phosphinic acid with a yield of 62%. On nitrating the new phosphinic acid with 45 equimolar amount of nitrating agent, a dinitro compound will be obtained in a yield 59%. And this dinitro compound could further be reduced to 2,8-diamino-10-hydroxy-5-methyl-5,10-dihydrophenophosphazine-10-oxide with hydrogen over 5% Pd/C. The effect of the amount of 5% Pd/C on the hydrogenation was investigated and the title compound was ultimately synthesized in a yield 70% by using the optimum amount of catalyst. All five intermediates obtained from this study were identified by NMR and mass spectroscopy. The title compound was proved to be a nonmutagenic aromatic diamine via Salmonella/mammalian microsome assay.

Key words: 5,10-Dihydrophenophosphazine, Synthesis, Structure identification, Mutagenicity, Salmonella/mammalian microsome assay