Abstract
α, β-Unsaturated alkenephosphonic acids, having even number carbon atoms from 6 to 14, were prepared by dehydrochlorination of β-chloroalkanephosphonic acids, which were obtained by the reaction of α-olefin and phosphorus pentachloride.
By the addition of adequate amount of phosphorus trichloride into the reaction mixture, the yield of by-product, 1, 2-dichloroalkane, was suppressed and β-chloroalkanephosphonic acid could be obtained in high yield (93%).
Dehydrochlorination of β-chloroalkanephosphonic acid could be conducted with morpholine, dimethylaniline and aniline (pKa<8.35), and α, β-unsaturated alkene-phosphonic acids were obtained, but with cyclohexylamine and triethylamine (pKa>10.6), the rupture of C-P bond occurred and α-olefin was obtained instead of alkenephosphonic acid.
