Reaction of 2,3-dihydro-1,3-6H-oxazine-2,6-dione with aliphatic amines and amino acids

Abstract

Reaction of 2,3-dihydro-1,3-6H-oxazine-2,6-dione (I) with amines in aqueous medium leads predominantly to N-substituted amides of (Z)-3-carboxylamino-2-propenoic acid. Isomeric 3-(N'-alkylureido)-2-propenoic acids are formed as by-products in the reaction of compound I with ammonia or methylamine; tert-butylamine affords ureido derivative as the sole reaction product. Secondary amines react with compound I substantially more rapidly than primary amines. In both cases the branching on the α-carbon decreases the reactivity distinctly while the branching on the β-carbon does not have a significant effect on the rate of aminolysis. The results of kinetic measurements of the reaction of compound I with amino acids are discussed n connection with the possible interaction of compound I with enzymes.

The Rut Pathway for Pyrimidine Degradation: Novel Chemistry and Toxicity Problems

“…The different chemical shifts of the species in panels A and B result from the fact that spectrum A was recorded in H 2 O, whereas spectrum B was recorded in DMSO. and unlabeled uracil but with 16 O 2 confirmed the presence of this species, which appeared to be the peracid of ureidoacrylate ( Fig. 4B and 5A).…”

“…An isotope shift in the 1D carbon spectrum indicated that an oxygen atom derived from molecular oxygen was bound to C-4 ( Fig. 3B) (16). A 1 H-15 N correlation spectrum showed that there was no 18 O bound to N-3 because the N-3 resonance failed to show the isotope shift of 0.138 ppm that would be expected if 18 O were directly bonded to it (data not shown).…”

“…The product was obtained by lyophilizing the methanol fraction. The presence of the correct product was confirmed by comparing 1 H-nuclear magnetic resonance (NMR) chemical shifts and coupling constants in dimethyl sulfoxide (DMSO) with published values (16). 1D 13 C NMR spectra.…”

“…His-tagged RutB protein was a kind gift from Tathagata Mukherjee Synthesis of Z-3-ureido-2-propenoic acid. Z-3-Ureido-2-propenoic acid (ureidoacrylate) was synthesized by adding 3 ml of 4 M ammonium hydroxide to 100 mg of 2,3-dihydro-1,3-6H-oxazine-2,6-dione (3-oxauracil) (Research Organics, Inc., Cleveland, OH) on ice as described previously (16). The reaction was allowed to proceed for 12 h at room temperature, after which 1 ml of 1 M NaOH was added, and the solution was lyophilized to dryness.…”

“…The RutB protein was assayed using 14 C-labeled RutA product as the substrate and monitoring by TLC as described above or using chemically synthesized ureidoacrylate (16) and monitoring the decrease in absorbance at 266 nm with extinction coefficients of 17,800 M Ϫ Cm Ϫ in 0.025 M HCl (16) and 18,300 in 40 mM Tris buffer (pH 8.2). Formation of ammonia was monitored by coupling to the glutamate dehydrogenase reaction and measuring NADPH oxidation (ammonia assay kit; Sigma, St. Louis, MO).…”