《Formation of fumaramic acid from asparagine in phosphate buffer》 was written by Talley, Eugene A.; Fitzpatrick, Thomas J.; Porter, William L.. Electric Literature of C4H5NO3 And the article was included in Journal of the American Chemical Society in 1959. The article conveys some information:
The product obtained by heating asparagine in pH 6.7 buffer (Na2HPO4, KH2PO4) 24 hrs. at 100° and previously regarded to be 4-carboxy-2-azetidinone (C.A. 51, 2715h), has been shown by chem. means, infrared absorption, X-ray powder diagram, and comparison with an authentic sample to be fumaramic acid (I). Absolute MeOH (10.7 g.) in 145 cc. dry C6H6 added dropwise to 51.0 g. fumaryl dichloride with stirring below 30°, kept overnight, and fractionally distilled gave the following fractions: (1) b18 62-71°, (2) b18 71-82°, (3) b18 82-4°, (4) b18 84-5° (di-Me fumarate); the combined fractions 2 and 3 stirred with cold H2O until emulsified, cooled, and filtered, and the residue washed with iced H2O gave 8.2 g. mono-Me ester (II) of fumaric acid, m. 144.0-4.5°. II (8.2 g.) shaken several min. at room temperature with 25 cc. concentrated NH4OH, kept 2 hrs., and evaporated in vacuo, the residue dissolved in H2O, redried, redissolved in H2O, and passed through Dowex 50 (H), the effluent and the washing from the column combined, concentrated at 40°, and allowed to stand, and the crystalline deposit recrystallized (H2O) and dried at 50° in vacuo yielded 6.3 g. I, which was identical with the product from asparagine. In the experiment, the researchers used 4-Oxo-2-azetidinecarboxylic acid(cas: 98019-65-9Electric Literature of C4H5NO3)
4-Oxo-2-azetidinecarboxylic acid(cas:98019-65-9) is one of azetidine.Azetidines (azacyclobutanes) constitute a well-known class of heterocyclic compounds. Azetidine scaffold has been discovered in several natural products.Electric Literature of C4H5NO3 Several pharmacologically important synthetic compounds also contain azetidine ring. Because of inherent ring strain, the synthesis of azetidines is a challenging endeavor.
Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics