NOVEL ACRYLAMIDO MONOMERS WITH HIGHER HYDROPHILICITY AND IMPROVED HYDROLYTIC STABILITY .1. SYNTHETIC ROUTE AND PRODUCT CHARACTERIZATION

The novel acrylamido monomer reported by our group (N-acryloylaminoeth oxyethanol, AAEE; Chiari et al., Electrophoresis 1994, 15, 177-186), f ound to combine high hydrophilicity with extraordinary resistance to a lkaline hydrolysis, has come under closer scrutiny due to unexpected a nd random autopolymerization while stored as a 1/1 v/v water solution at 4 degrees C (possibly due to a greater oxidability of the ether gro up). We have additionally found a unique degradation pathway of the mo nomer, called ''1-6 H-transfer'', by which the C-1 (on the double bond site), by constantly ramming against the C-6, next to the ether oxyge n (O-7, which in fact favors the transfer of the hydrogen atom by C-1) , produces radicals which more efficiently add to the monomer favoring autopolymerization and cross-linking. A number of novel monomers is p roposed while maintaining the other unique chracteristics of AAEE. One of them, N-acryloylaminopropanol, offers all the unique, special qual itites of AAEE, without the noxious aspects of autopolymerization. Add itionally, a synthetic route was optimized, yielding an essentially pu re product in a single reaction step, with a yield >99% and an equival ent purity (>99%). The synthesis consists in reacting acryloyl chlorid e at -40 degrees C in presence of a twofold molar excess of aminopropa nol and in ethanol (instead of methanol) as solvent. Other solvents, a s well as the use of triethylamine for neutralizing the HCl produced, were found to give a variety of undesired byproducts.