Hydantoin

Structural formula
General
Surname	Hydantoin
other names	Imidazolidine-2,4-dione ( IUPAC ); 2,4-dioxotetrahydroimidazole; Glycolylurea; 2,4 (3 H , 5 H ) -Imidazoldion;
Molecular formula	C 3 H 4 N 2 O 2
Brief description	colorless solid
External identifiers / databases
EC number	207-313-3
ECHA InfoCard	100.006.650
PubChem	10006
Wikidata	Q418082
properties
Molar mass	100.08 g · mol -1
Physical state	firmly
Melting point	221-222 ° C
solubility	poorly soluble in water
safety instructions
GHS labeling of hazardous substances	no GHS pictograms
	no GHS pictograms
H and P phrases	H: no H-phrases
	P: no P-phrases
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Hydantoin is a saturated, heterocyclic compound and a derivative of imidazole . The lactam (cyclic amide ) hydantoin can be regarded as a derivative of urea or the amino acid glycine . It crystallizes easily and forms colorless crystals with a slightly sweet taste.

History & occurrence

As part of his work on the breakdown products of uric acid , Adolf von Baeyer obtained a white crystalline powder by reducing allantoin (primary breakdown product of uric acid) with hydrogen iodide , which he called hydantoin ( IUPAC : imidazolidine-2,4-dione ).

Uric acid - allantoin - hydantoin

Extraction and presentation

According to F. Urech (1873) hydantoin can be obtained by reacting glycine with an isocyanate (see also Friedrich Wöhler , urea synthesis ). Glycine condenses with isocyanate to form hydantoic acid , which splits off when heated in acidic water.

properties

Hydantoin is stable under normal conditions. In water it is acid-catalyzed hydrolyzed as dilactam to hydantoic acid .

use

Hydantoin is used, among other things, for the synthesis of amino acids and as a softener for textiles and as a sizing agent. In a basic medium, the methylene group in position 5 can be deprotonated, so that a condensation reaction with aldehydes or ketones takes place. Hydrogenation and hydrolysis of the condensation products give racemic 2-amino acids.

Use of the derivatives

N -halogenated hydantoin derivatives

N -Halogenated derivatives of hydantoin are used as disinfectants .

Some derivatives are important as anticonvulsants (anti-epileptic drugs).

Polyhydantoins have become known as heat-resistant plastics.

literature

Adolph Baeyer: Preliminary note on the Hydantoïn . In: Justus Liebig's Annals of Chemistry . tape 117 , no. 2 , 1861, ISSN 1099-0690 , p. 178-180 , doi : 10.1002 / jlac.18611170204 .

Individual evidence

↑ ^a ^b ^c Datasheet Hydantoin, 99% at AlfaAesar, accessed on December 6, 2019 ( PDF )(JavaScript required) .
↑ ^a ^b Data sheet hydantoin (PDF) from Merck , accessed on December 21, 2019.
^ F. Urech in Justus Liebigs Annalen der Chemie und Pharmacie Ann. 165, 1873, p. 99.

[Alfa-1] Datasheet Hydantoin, 99% at AlfaAesar, accessed on December 6, 2019 ( PDF )(JavaScript required) .

[Merck-2] Data sheet hydantoin (PDF) from Merck , accessed on December 21, 2019.

[urech-3] F. Urech in Justus Liebigs Annalen der Chemie und Pharmacie Ann. 165, 1873, p. 99.