Imidazolidine-2,4-diones

Hydantoin — see also Imidazolidine-2,4-dione Hydantoin, 3-aryl-5-benzyl-structure, 5, 351... 

K. Ienaga, K. Nakamura, A. Ishii, T. Taga, Y. Miwa, F. Yoneda, The Stepwise Mammalian Oxidation of the Hydantoin l-Methyl-imidazolidine-2,4-dione into Methylimi-dazolidinetrione via 5-Hydroxy-l-methyl-imidazolidine-2,4-dione , J. Chem. Soc. Perkin Trans. 1 1989, 1153-1156. 

Sodio-5-(5 -nitro-2 -furfurylideneamino)imidazolidin-2,4-dione, 2903 Sodium abietate, 3799 Sodium acetate, 0775... 

Chemical Name l- [5-(4-Chlorophenyl)furan-2-ylmethylene]amino -3-[4-(4-methylpiperazin-l-yl)butyl]imidazolidine-2,4-dione dihydrochloride... 

Preparation of 3-[5 -amino-(/Y-l-butyloxycarbonyl)- -pentanyl]-5-[(indol-3-yl) methyl]-imidazolidine 2,4-dione... 

Cases in which more than one tautomerizable substituent are present in the imidazole ring are common, but tautomerism studies of such compounds are less so. Work on the hydantoins (imidazolidine-2,4-diones) is not at all definitive UV and IR studies suggest the dioxo form (78), but evidence for the existence of other tautomeric structures (79,80) is not convincing (Scheme 26). ImidazoIidine-4,5-diones also exist as the dioxo forms. NMR studies show that the 2-benzyl derivatives must exist in solution as the NH form (81 R = H, Me), and the methoxy derivatives, similarly, are NH (82) rather than OH (83) derivatives (Scheme 26). 

Z)-l-Acyl-3-methyl-5-(cyanomethylidene)imidazolidine-2,4-diones such as 807 readily undergo 1,3-dipolar cycloadditions with various 1,3-dipoles. The final products depend both on the nature of the dipoles and the dipolarophiles. Thus, spirohydantoins 808 and 809 are formed under neutral conditions with diazomethane or a nitrile oxide whereas further isomerization occurs under either basic or acidic conditions leading to acylureas such as 811 via 810 (Scheme 200) <2001HCA3403>. 

Iprodione, 3-(3,5-dichlorophenyl)-N-isopropyl-imidazolidine-2,4-dione-l-carboxamide (30), is actually a hidantoin derivative (Sauli, 1970). 

Glycine ester (31) is reacted with 3,5-dichlorophenylisocyanate (32) to yield the ethyl ester of 5-(3,5-dichlorophenyl)hidantoic acid (33). By the cyclisation of this product 3-(3,5-dichlorophenyl)imidazolidine-2,4-dione (34) is formed, which with isopropylisocyanate, yields the end product. 

---