Methods of preparing activated polymers having alpha nitrogen groups

A method of preparing a polymer having a lone electron pair-containing moiety thereon, comprising:

• reacting a polymer of formula (I)
• R2-R1-(L1)n-LG (I)
• wherein
• R1 is a substantially non-antigenic polymer;
• R2 is a capping group, LG or LG-(L1)n-;
• L1 is a bifunctional linker;
• LG is a leaving group selected from the group consisting of
• wherein R3 is methyl, halogen, nitro, fluoromethyl, difluoromethyl, trifluoromethyl, or substituted carboxyl;
• a multi-halogen substituted benzenesulfonyl;
• mesylate;
• brosylate;
• tresylate, and nosylate;
• and
• n is 0 or positive integer,
• with a compound of Formula (III) in an aqueous base at a temperature of from about 45 to about 50° C. and for a reaction time of less than about 18 hours,
• wherein the compound of Formula (III) is
• wherein
• Z is NR7;
• X is O, S or NR8;
• m is a positive integer;
• R4 is H;
• R5, R6, R7 and R8 are independently selected from the group consisting of H, C1-6 alkyls, C3-12 branched alkyls, C3-8 cycloalkyls, C1-6 substituted alkyls, C3-8 substituted cycloalkyls, aryls, substituted aryls, aralkyls, C1-6 heteroalkyls, substituted C1-6 heteroalkyls, C1-6 alkoxy, phenoxy and C1-6 heteroalkoxy,
• provided that R4 and R7 are both not H;
• and
• the aqueous base is selected from the group consisting of NaOH, KOH, LiOH, Mg(OH)2, Ca(OH)2 and mixtures thereof,
• wherein
• 10 molar equivalent of compound of Formula (III) is employed for each equivalent of LG;
• and
• the purity of the polymer having the lone electron pair-containing moiety thereon formed by said method is greater than 95%.