Kinetics and Mechanism of Oxidation of l-Proline by N-Bromosuccinimide in Aqueous Acidic Medium

Abstract

Kinetics of oxidation of L-poline by N-bromosuccinimide (NBS) in aqueous acidic medium and waterÀalcohol solvent mixtures were performed. The reaction was first order dependent on both [proline] and [NBS]. The rate of reaction was inversely dependent upon [H + ] through the pH range 2.6À3.3 and varied with the cosolvent according to the order MeOH > EtOH. The conjugate base of amino acid was considered as the main reactive species. An inner-sphere mechanism in which the conjugate base of amino acid was attached by NBS to form the precursor intermediate complex was proposed.

Vanadium(v) oxoanions in basic water solution: a simple oxidative system for the one pot selective conversion ofl-proline to pyrroline-2-carboxylate

“…8 In fact, classic Strecker degradation agents, such as ninhydrin or 1,2dicarbonyl compounds, do not react with L-proline as well as other secondary amino acids. 1 On the other hand, the oxidation of L-Proline by organic oxidants, such as N-bromosuccinimide in water 9 or iodosylbenzene in various solvents, 10 yields 2-pyrrolidinone. The same product has been obtained by treatment of L-proline with NaIO 4 in aqueous H 2 SO 4 (pH = 2).…”

Degradation of Chemical Threats by Brominated Polymer Networks

“…The high reactivity of N -bromosuccinimide (NBS) as an oxidant and brominating agent in a multitude of reactions is well-known. − In this work, we replicated the NBS reactivity with its polymeric counterpart, brominated polysuccinimide (alternatively called polymaleimide, PMAi) and its copolymers, with a focus on the processability of the polymer into functional networks and films that can be incorporated into multilayered fabrics and other items capable of degrading chemical threats. Polymaleimides are conventionally prepared by either homopolymerization of maleimide, , or by thermolysis or hydrolysis of substituted maleimide homopolymers. − As an alternative, to avoid the need to polymerize maleimide (a relatively expensive starting material), polymaleimide (PMAi) synthesis with high degrees of conversion has been reported via amidation of poly­(maleic anhydride) homopolymers by urea . We investigated both the copolymerization of monomeric maleimide with divinyl cross-linkers and amidation of a commercially available, film-forming maleic anhydride copolymer, poly­(ethylene- alt -maleic anhydride) (PEMA).…”

Efficient and Environmentally Benign Oxidative Cleavage of Pyrrolidine-2-methanols to γ-Lactams Using 2-Iodobenzamide as a Catalyst and Oxone

“…The oxidation of N-protected proline 10 produced only 4% of 8a after 7 h (Chart 3d). Proline (11) did not react under these reaction conditions after 36 h (Chart 3e), although 11 slowly reacted with the trivalent iodine reagent [(PhIO) n ] to produce 2-pyrrolidone in moderate yield after 2 d. 8) These results indicate that the oxidative cleavage reaction of N-protected pyrrolidine-2-methanols with a catalytic amount of 6 and Oxone proceeded smoothly to give N-protected 2-pyrrolidone.…”

“…In addition, oxidation can occur selectively at the 2-position to produce regioselective lactams, such as 2-pyrrolidone and 2-pipelidone. Oxidative transformations of carboxylic acids 1 to 3 have already been reported, including stoichiometric oxidations, [7][8][9][10][11] transition-metal catalyzed oxidations, [12][13][14][15] photochemical 16,17) and electrochemical 18,19) reactions. The transformation of methanols 2 to 3 has been achieved using transition metal-catalyzed [20][21][22] and non-catalytic 23) oxidations.…”