Water-soluble non-ionic triarylbismuthanes. First synthesis and properties

Abstract

The synthesis and properties of some new water-soluble non-ionic triarylbismuthanes are described. o-, m- and p-Tris(methoxymethoxyphenyl)bismuthanes 1a–c are prepared from BiCl₃ and the corresponding organolithium or Grignard reagents. Oxidative chlorination of 1a–c with SO₂Cl₂ affords tris(methoxymethoxyphenyl)bismuth dichlorides 2a–c, which are deprotected by aqueous HCl to give tris(hydroxyphenyl)bismuth dichlorides 3a–c. Treatment of tris(3-hydroxyphenyl)bismuth dichloride 3b with NH₂NH₂ yields tris(3-hydroxyphenyl)bismuthane 5, which dissolves in dilute aqueous NaOH. N,N-Bis(2-tert-butyldimethylsiloxyethyl)benzenesulfonamide, prepared from benzenesulfonyl chloride and silyl-protected diethanolamine, is ortho-lithiated and reacted with ⅓ equiv. of BiCl₃ to give Ar₃Bi 9a {Ar = 2-[N,N-bis(2-tert-butyldimethylsiloxyethyl)sulfamoyl]phenyl}. m-Phenylene-bridged Bi₂- and Bi₃-polybismuthanes 12 and 13 are prepared by the reaction between ortho-lithiated 9a and Ar₂BiI 10. Desilylation of 9a, 12 and 13 by Bu₄NF or p-TsOH·H₂O in EtOH leads to the corresponding bismuthanepolyols 11, 14 and 15. The reaction between benzene-1,3-disulfonamide 16 bearing the silyl-protected bis(2-hydroxyethyl)amino side chains and ⅓ equiv. of BiCl₃ affords tris{2,4-bis[N,N-bis(2-tert-butyldimethylsiloxyethyl)sulfamoyl]phenyl}bismuthane 17, which is deprotected by p-TsOH·H₂O to yield tris{2,4-bis[N,N-bis(2-hydroxyethyl)sulfamoyl]phenyl}bismuthane 18. Compounds 11, 14 and 15 are only slightly soluble in water, but compound 18 is fairly soluble.