Direct amidation of poly(gamma-glutamic acid) with benzylamine in dimethyl sulfoxide.
Partially benzylamidated, amphipathic poly(gamma-glutamic acid) (BzPGA) was synthesized from poly(gamma-glutamic acid) (PGA) and benzylamine by direct amidation in dimethyl sulfoxide (DMSO). Benzylamine and PGA were heated in DMSO for 1 to 26 h at temperatures between 110 and 130 degrees C, producing derivatives of various degrees of benzylamidation as a function of the reaction time and temperature. Neither any carboxyl-activating agent nor catalyst is needed for the reaction to proceed. After purification by dialysis, the product was identified by 1H and 13C 1D and 2D NMR in DMSO-d(6). BzPGA prepared by the new direct amidation method was identical to that obtained with a conventional carbodiimide-mediated reaction in water. The one-pot amidation procedure described in the present article can probably be applied to the synthesis of amides from other amines and carboxylic acids.
Novak
Levente
L
Department of Colloid and Environmental Chemistry, University of Debrecen, P.O.B. 31, H-4010 Debrecen, Hungary. lnovak@dragon.unideb.hu
Banyai
Istvan
I
Fleischer-Radu
Judit Eva
JE
Borbély
Janos
J
D000577:Amides / Q000737:chemistry; D001596:Benzylamines / Q000737:chemistry*; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D011099:Polyglutamic Acid / Q000138:chemical synthesis / Q000737:chemistry*
D000577:Amides; D001596:Benzylamines; C521884:benzylamidated poly(gamma-glutamic acid); D011099:Polyglutamic Acid; C030796:benzylamine; D004121:Dimethyl Sulfoxide