115169-06-7Relevant academic research and scientific papers
Syntheses de phosphobetaines amphiphiles neutres a distances intercharge variables
Germanaud, Laurent,Brunel, Sylvian,Chevalier, Yves,Le Perchec, Pierre
, p. 699 - 704 (2007/10/02)
Neutral amphiphilic phosphonato- and phosphinatobetaines having different interionic distances are synthesized.Two paths for this synthesis have been studied. 2-(Ethoxy or phenyl) 2-oxo 1,2-oxaphospholanes react with lipophilic tertiary amines at 150 deg C, giving rise to mixtures of phosphobetaines and oxaphospholanate ammonium salts.Lewis acids increase the reaction rate but cannot change the selectivity.The specific production of phosphobetaines is achieved by a three steps sequence: the Arbusov reaction is applied to α,ο-dibromoalcanes and triethylphosphite or phenyldiethylphosphonite, providing ο-bromophosphonates in high yield.Tertiary amines are then condensed, followed by a bromide to hydroxide ions exchange on an anion exchange resin.Phosphobetaines are then specifically formed by thermal elimination of ethanol above the critical micellar concentration.Howewer, when Hoffmann elimination competes with basic hydrolysis of the phenylphosphinic ester groups, acidic hydrolysis is preferred, followed by neutralization with an OH- anion exchange resin.This preparative specific synthesis procedure affords pure, neutral and inorganic salt free zwitterionic compounds for a whole series of homologues.The physical properties of such compounds are believed to be designed upon the chice of the substituents (alkyl chain length, interionic methylene number, ethoxy or phenyl substituent at the phosphorous atom).
