Fire retardant halohydrinphosphonate prepn. - using ethylenic cpds. and sodium hypochlorite

摘要

Prepn. of halohydrin phosphonates of formula (I) is described. (where n = 0 or 1, X is Cl or Br, R is lower alkyl, R1 is H or lower alkyl, R2 and R3 are H, lower alkyl, or a gp. -P(O)(OR)2 or a lower alkyl radical substd. by this gp. R1 is lower alkyl provided only one of R2, R3 contains is a phosphonate gp). The process comprises reacting a cpd. of formula (II) with an alkali metal hypohalide in an aq. medium at an acid pH. Novel halohydrin diphosphonates have the formula (III) where R, R1 and X are as above, n1 is 1 and one of R4R5 is H or lower alkyl, the other a gp. -P(O)(OR1)2 are an alkyl radical substd. by such a gp.). The cpds. are used as fire retarding agents in polyurethane foams.