Development of a Scalable Method for the Synthesis\nof Ethoxy(pentafluoro)cyclotriphosphazene

Ethoxy(pentafluoro)cyclophosphazene\n(<b>1</b>) exhibits excellent\nflame retardancy and various biological activities, and there are\nnumerous synthesis methods available. However, most of these methods\nhave certain problems and shortcomings, such as the use of expensive\nraw materials and toxic and harmful reagents. To address these issues\nand uncertainties, we reported the development of a facile and sustainable\nsynthesis method of <b>1</b>, which involves only two concise\nchemical steps. In this process, the first step contains the reaction\nof hexachorocyclotriphosphazene (<b>3</b>) with sodium fluoride\nto yield hexafluorocyclotriphosphazene (<b>2</b>). The second\nstep includes ethoxylation using an ethoxylation reagent, ethanol,\nand sodium hydroxide as an acid-binding agent to produce <b>1</b> with good quality and an overall yield of 76%. Several advantages\nare offered by this new synthetic approach, including good reactivity,\nhigh yield, low cost, environmental friendliness, and, finally, being\nindustrially viable. The optimized process has been successfully demonstrated\non a large scale to support the development of the new energy electric\nvehicle industry.