Abstract

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Title:: Synthesis of Flame Retardants 3-(Hydroxyphenylphosphinyl) Propionic Acid Catalyzed by Ionic Liquid

Author(s):: Luo Xuan; Shi Hongli; Zhou Hao; Zhang Shilei; Yang Jinfei; Zhi Huizhen; School of Chemistry and Materials Science,Nanjing Normal University,Nanjing 210097,China

Keywords:: ionic liquid; dichlorophenylphosphine; 3-( hydroxyphenylphosphinyl) propionic acid; flame retardants

Abstract:: 3-( hydroxyphenylphosphinyl) propionic acid ( CEPPA) was synthesized by a two-step procedure: Phenyl phosphonic dichloride ( DCPP) was first synthesized using phosphorus trichloride and benzene as raw materials，and triethyl benzyl ammonium chloride-aluminum chloride( ［BnEt3N］Cl － xAlCl3 ) as catalyst． The optimum conditions for the first step are as follows: n( PCl3 ) ∶ n( C6H6 ) ∶ n( ［BnEt3N］Cl － xAlCl3 ) = 3∶ 1∶ 0. 025，At the reflux stage，the reaction temperature was 72℃—76℃，the reaction time was 6 h，and the yield of DCPP was up to 81. 1%． The optimum conditions for the second step by changing the order of the reactants and adjusting the reaction temperature were as follows: n ( acrylic acid) ∶ n( DCPP) = 1. 30∶ 1. 00; the reaction temperature was 70℃ － 80℃ and the reaction time was 1. 5 h － 2 h at the dropping stage; then reacting at 90℃ for 1 h; at the hydrolysis reaction stage，the reaction temperature was 92℃ － 95℃，and the reaction time was 4 h，the yield of CEPPA was up to 91%． The problem of agglomeration was easy to be solved in this procedure．