Selective reversible protection of ethylenediamine for the synthesis of methacryl-based monomers

Summary

The hydrophilic monomers, 2-aminoethylmethacrylamide (AEMA), N,N-bis (2-hydroxypropyl) aminoethylmethacrylamide (HPAEMA) and N,N,N′-tris(2-hydroxypropyl) ethylenediamine methacrylate (HPEDM), were prepared through selective and reversible protection of ethylenediamine. Ethylenediamine was selectively protected by trimethylsilylation to give N,N,N′-tris-and N,N-bis(trimethylsilyl) ethylenediamine. Stoichiometric addition of methacryloyl chloride to N,N,N′-tris (trimethylsilyl) ethylenediamine gave exclusively N,N-bis (trimethylsilyl) aminoethylmethacrylamide (BTAEMA) in quantitative yield. Desilylation with methanol also produced AEMA in quantitative yield. Treatment of AEMA with propylene oxide produced HPAEMA monomer in 92.4% yield. N,N-Bis (trimethylsilyl) ethylenediamine was treated with propylene oxide, and desilylated to give 92.8% yield of N,N-bis(2-hydroxypropyl) ethylenediamine. Upon treatment with glycidyl methacrylate, HPEDM monomer was produced in 75.6% yield. The selective and reversible protection of ethylenediamine provides a convenient and efficient method for generating asymmetrically substituted ethylenediamine-based monomers.