Examples of new synthetic routes to pendant ester-ether derivatives of α-hydroxymethylacrylate polymers

Summary

Three routes to new ester-ether derivatives of ethyl α-hydroxymethylacrylate (EHMA) and t-butyl α-hydroxymethylacrylate (TBHMA) were investigated. The first approach involved the preparation of chloroacetate derivatives of EHMA and TBHMA as intermediates followed by attempted etherification of the chloroacetate group. All attempted nucleophilic reactions of ethyl α-chloroacetoxymethacrylate (ECAM) and t-butyl α-chloroacetoxymethacrylate (TBCAM) gave Michael-type substitution products with loss of the α-chloroacetyl substituent. Polymer substitution was therefore investigated. Bulk polymerization of ECAM with AIBN gave unexpectedly high molecular weight polymer with a number average value of 1.15 million. This homopolymer was substituted with 4-phenylphenol in excellent conversion. The second approach involved the reaction of ethyl α-chloromethylacrylate (ECMA) with α-ethers of acetic acid sodium salts using phase transfer catalysis. The methoxyacetate derivative was prepared and polymerized to give a polymer with a number average molecular weight of 260,000. The third route to ester-ether derivatives involved three steps: reaction of t-butylchloroacetate with an alcohol to give the ether, conversion of the t-butyl group to the acid chloride, and reaction of the acid chloride with EHMA or TBHMA. The 2-(4-phenylphenoxy)acetate derivative of EHMA was prepared using this method, and converted to high polymer.