The Dehydration of Hydantoin-5-propionic Acid

Abstract

Oxidation of Homocysteine Hydantoin.-Fifty mg. of homocysteine hydantoin was titrated with 2.9 cc. of 0.1 N iodine solution which is 93% of the theoretical. The crystals which precipitated were collected by filtration, dried ^nd gave a m. p. of 201-203°. A mixed m. p. with homocystine hydantoin gave no depression.Oxidation of Cysteine Hydantoin.-Sixty-four and a half mg. of cysteine hydantoin consumed 4.4 cc. of 0.1 N iodine solution which is the theoretical quantity. The crystals were collected on a filter and dried. The com-pound decomposed above 300°and gave a positive disulfide test.

2-Phenylaspartic acid derivatives from .beta.-lactams

“…H. A7,2-Diphenylaspartic Acid (7).-A mixture of 15 g (0.05 mol) of 2 and 0.16 mol of NaOH in 230 ml of 65% aqueous dioxane was heated under reflux for 3 hr and then concentrated. After adding 160 ml of 1 A7 HC1, 10 g (70%) of 7 precipitated.…”

“…Refluxing 3 for 5 min in a 1.6% NaOH (2.4 equiv) aqueous EtOH solution allowed selective hydrolysis of the 4-carbethoxy group, giving an 80% yield of 1-ethyl N,2-diphenylaspartate (6) the ring cleavage of 2 with concentrated H2SO4. More drastic hydrolysis of either 2 or 3 with excess NaOH in refluxing aqueous dioxane produced N,2-diphenylaspartic acid (7). Other investigators3 obtained N-phenylaspartic acid by hydrolysis of 2,2-dicarbethoxy-l-phenyl-4-oxoazetidine with KOH, followed by decarboxylation.…”

“…These values require a large population of restricted rotational conformations with the plane of the carbonyl group bisecting the H-C-H bonds of the methylene group.10 Conformational restrictions imposed by rotational hindrance of the two benzene rings, and probably enhanced by intramolecular hydrogen bonding of the acidic hydrogen to the adjacent carbonyl group, allow a preferred conformation for the 2-phenylaspartic acid derivatives which approaches that of the cyclic compounds. <* See Experimental Section for the letters: (1) isolated from the EtOAc soluble fraction in method H as the piperazinium salt formula, (CuHnN03)2•CeHioNs; (2) MeOH was employed as the reaction solvent; (3) 75% aqueous 2-PrOH was used as the reaction solvent in method ; (4) prepared by the action of SOCL on 19, followed by treatment with NH4OH; (5) concentration of the reaction mixture in method H, followed by solution of the residual oil in H2O and adjusting pH to ~4r-5 gave the solid; (6) precipitated by concentrating the aqueous layer from 8; (7) H20 soluble fraction from 9. 2-Phenylaspartic Acid Derivatives from /3-Lactams…”

Synthesis and characterization of a methacrylate monomer with a thiohydantoin structure

“…(2-thiohydantoin-4-yl)propionic acid (THPA) A thiohydantoin derivative, THPA, was synthesized according to the method described by Szabo and Karabinos [15] and Duggan et al [16].…”