Bisureas

Recently, Kelly and Kim have compared the relative binding affinities of urea and bisurea 33 and 34 with carboxylate and its isosteres. They find that both hosts preferentially associate with functionalities according to the following ranking ArOPO - > ArPO - > ArCOj > ArP(OH)02 > Ar0P(0H)02 > ArSOj > ArSOj 5-lactone > ArNOj. 

CO to the depicted complex the chloride is displaced by CO and moves to the bisurea binding pocket. After insertion ofthe CO into the palladium at higher temperatures the chloride moves back to the palladium. This sho vs that hydrogen bond motifs can also be used to construct bidentate ligands, but one should be a vare of the noninnocent character. 

Projection along the b axis showing the hydrogen-bonding interactions within the puckered rhodizonate-bisurea-water layer of [(n-... 

SYNS 1.1-DIUREIDISOBUTANE DIUREIDO-ISOBUTANE IBDU ISOBUTYLDIUREA ISOBUTYLENEDIUREA l,l -ISOBUTYLIDENE-BISUREA ISODUR N,N"-(2-METHYLPROPYL-IDENE)BISUREA (9CI)... 

Suramin Sodium. Suramin. sodium is a high-molecular-weight bisurea derivative containing six sulfonic acid groups as their sodium salts. It was developed in Germany shortly after World War I as a by-product of research effons directed toward the development of potential antiparasitic agents from dyestuffs. 

In 1959, Belgian chemists worked out another method of synthesizing amine 194 by heating phenyl hydrazinecarboxylate (59BSB432). These authors, and then Lutz (64JOC1174), finally proved that the product obtained in all cases described earlier has structure 194. The results of Guha and De (24JCS1215) were revised, since they proposed the formation of urazine 197 from carbohydrazide with urea. The product thus obtained was found to be bisurea 195. 

BRN 1908981 Diureidoisobutane 1,1-Diureidisobutane EINECS 228-055-8 IBDU 1,1 -lsobutylidenebisurea Isobutyidiurea Isobutylenediurea Isobutylidene diurea N,N"-(lsobutylidene)diurea Isodur N,N -(2-Methyl-propylidene)bisurea Urea, 1,1 -isobutylidenedi- Urea, N,N"-(2-methylpropylidene)bis-. 

The crude product obtained was purified by column chromatography over silica gel with 1 1 ethyl acetate-hexane as the eluant to secure the final compound (229) in 55% yield. Careful isolahon and characterization showed that one of the major by-products of this reaction to be the bisurea derivative (259) in yields of up to 20%. We explored phe-nylchloroformate as a substitute to triphosgene in the preparation of unsymmetrical urea derivatives. Phenylchloroformate (260) in the presence of an appropriate base on reaction with an amine (241) gave the corresponding carbamate, which on further reaction with A-methyl hydroxylamine gave a urea derivative (229). However, the formation of bisurea... 

Van Esch. J. DeFeyter, S. Kellogg, R.M. DeSchryver, F. Feringa. B.L. Self-assembly of bisurea compounds in organic solvents and on solid substrates. Chem. Eur. J. 1997, 3. 1238-1243. 

Ranganathan. D. Lakshmi. C. Karle. I.L. Hydrogen-bonded self-assembled peptide nanotubes from cystine-based macrocyclic bisureas. J. Am. Chem. Soc. 1999. 121 (26), 6103-6107. 

Botterhuis NE, Karthikeyan S, Veldman D, Meskers SCJ, Sijbesma RP (2008) Molecular recognition in bisurea thermoplastic elastomers studied with pyrote-based fluorescent probes and atomic force microscopy. Orem Commun 2008(33) 3915-3917... 

Yang J, Dewal MB, Shimizu LS (2006) Self-assembling bisurea macrocycles used as an organic zeolite for a highly stereoselective photodimerization of 2-cyclohexenone. J Am ChemSoc 128(25) 8122-8123... 

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