Organo:phosphorus derivs. of 2,4-di:tert:butyl-phenol

摘要

Prodn. of organophosphorus derivs. (I) of 2,4-di-tert.-butylphenol, contg. a high proportion of organophosphorus derivs. of biphenyl, comprises (a) reaction of a 4,4'-dihalobiphenyl (II) (with halogen atomic wt. at least 35) with Mg to form the corresp. Grignard reagent, followed by (b) reaction with phosphorous acid bis-(2,4-di-tert.-butyl-phenyl)-ester chloride of formula (III) to form a mixt. in which at least 50 wt.% of the phosphorus is in the form of tetrakis-(2,4-di-tert. -butylphenyl) -4,4'-biphenylene-diphosphonite of formula (IV) (as determined by 31P-NMR). Pref. at least 60 wt.% of the P is in the form of cpd. (IV), stage (b) is carried out at 30 to +30 deg.C pref. -20 to +20 deg. C, (a) is carried out without an entraining agent, using finely-divided Mg which is kept in suspension, pref. by agitation, esp. pref. by ultrasonic means, amt. of Mg is 2.2-3 equivs. per mol. (II) and the halogen in (II) is Cl or Br.