Isolation and X-ray structure of the intermediate dihydroxyimidazolidine(DHI) in the synthesis of glycoluril from glyoxal and urea.

Grillon, E.; Gallo, Rafael D. C.; Pierrot, M.; Boileau, J.; Wimmer, E.

doi:10.1016/0040-4039(88)85322-x

Cited by 63 publications

(44 citation statements)

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“…[15] The macrocycle was isolated from the reaction mixture by simple filtration; the resulting solid did not require any purification except washing with solvent. The starting monomer, 2,4-dimethylglycoluril, [16,17] and its precursor, 4,5-dihydroxyimidazolidin-2-one, [18,19] were also prepared before. During our attempts to prepare these two heterocyclic compounds according to the published procedures, we found that there are some important aspects to which one should pay attention in order to avoid possible difficulties.…”

Section: Resultsmentioning

confidence: 99%

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Anion‐Free Bambus[6]uril and Its Supramolecular Properties

Švec

Dušek

Fejfarová

et al. 2011

Chemistry A European J

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Methods for the preparation of anion-free bambus[6]uril (BU6) are presented. They are based on the oxidation of iodide anion, which is bound inside the macrocycle, utilizing dark oxidation by hydrogen peroxide or photooxidation in the presence of titanium dioxide. Anion-free BU6 was found to be insoluble in any of the investigated solvents; however, it dissolves in methanol/chloroform (1:1) or acetonitrile/water (1:1) mixtures in the presence of the tetrabutylammonium salt of a suitable anion. The association constants with halide ions, BF(4)(-), NO(3)(-), and CN(-), were measured by (1)H NMR spectroscopy. The highest association constant (8.9×10(5) M(-1)) was found for the 1:1 complex of BU6 with I(-) in acetonitrile/water mixture. A number of crystal structures of BU6 complexes with various anions were obtained. The influence of the anion size on the macrocycle diameter is discussed together with an unusual arrangement of the macrocycles into separate layers.

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Section: Resultsmentioning

confidence: 99%

“…At higher reaction conversions, BU6·I À is not pres- ent in sufficient amounts. As a result, I 2 remains as a dominant side product in the reaction mixture or is possibly oxidized further by species, such as H 2 O 2 , [16,17,36,37] produced in the irradiated solutions.…”

Section: Wwwchemeurjorgmentioning

confidence: 98%

Anion‐Free Bambus[6]uril and Its Supramolecular Properties

Švec

Dušek

Fejfarová

et al. 2011

Chemistry A European J

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“…It has been reported (28,29) that the synthesis of these compounds in aqueous solution at room temperature and in presence of mineral acids requires long reaction times (12Á48 h) to obtain yields ranging from 20 to 50%. Only in one case (product 3a) it has been reported (30) that the reaction occurs in 30 minutes giving the product in yield more than 96%; we repeated this experiment but, in our hands, the yield was only 40%.…”

Section: Resultsmentioning

confidence: 99%

A green synthesis of glycoluril derivatives in aqueous solution with recycle of the waste

Micheletti

Delpivo

Baccolini

2012

Green Chemistry Letters and Reviews

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A series of glycoluril derivatives have been synthesized in water at room temperature from urea and 1,2-dicarbonyl compounds in the presence of phosphoric anhydride. The reaction time is about 10 minutes using one mole of 1,2-dicarbonyl compound, three moles of urea, and half mole of P 4 O 10 , but the reaction occurs also, even if with longer reaction times, with very small amounts of P 4 O 10 which is recovered at the end of reactions. In fact, several catalytic turnovers can be performed using the same reaction solution obtained after separation by simple filtration of the glycolurils.

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“…The effect of temperature (20-90 °С), reaction time (0.5 to 7.5 h), and рН of the medium (pH 3-9) on the yields of the target DHIT were investigated. It was found that com pound 1а is formed in 47-50% yield after 30 min at рН 4 and 50 °С unlike related DHI, 3 which is prepared at рН 6.5-7.5 and 90 °С. Compounds 1b,c were obtained in 75-78 and 60-63% yields, respectively, after 2 h at рН 5-6 and 50 °С analogously to 1,3 diethyl DHI, which was obtained under identical conditions, but after 7 h. 19 1,3 Dimethyl DHI was obtained at both рН 4 after 7.5 h and рН 8-9 after 3 h at room temperature.…”

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confidence: 98%

“…The decision between them can be made by, e.g., checking whether the geometry of the hydrogen bonded associate is preserved upon replacement of sulfur atom by oxygen atom of similar nature. To this end, we car ried out a high precision X ray diffraction study of 1a and related DHI 1a´, 3 which contains an urea instead of thiourea fragment.…”

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The synthesis, structure, and electron density distribution in crystals of 4,5-dihydroxyimidazolidine-2-thiones

et al. 2009

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4,5 Dihydroxyimidazolidine 2 thiones were synthesized and their structural peculiarities were studied. A comparative analysis of dihydroxyimidazoli dine 2 thione and its carbonyl analog performed in the framework of detailed investigation of the electron density distribution in the corresponding crystals revealed the reason for different number and geometric parameters of the hydrogen bonds formed by the (thio)carbonyl groups in the crystals.Key words: cis and trans isomers, 4,5 dihydroxyimidazolidine 2 thiones, 1 Н and 13 С NMR spectroscopy, X ray analysis, electron density distribution function, topological analysis. 4,5 Dihydroxyimidazolidine 2 ones (DHI) are wide ly used as building blocks for the synthesis of various het erocyclic compounds, in particular, tetrahydroimidazo [4,5 d]imidazoles, 1-6 octahydroimidazo[4,5 e] 1,2,4 tri azines, 7,8 and tetrahydroimidazo[4,5 с] 1,2,5 thiadi azoles. 9, 10 The use of thio analogs of DHI, i.e., 4,5 dihydroxyim idazolidine 2 thiones (DHIT), in the synthesis of the cor responding heterocyclic systems is less studied because these compounds are less available. Among DHIT, those containing various aryl substituents at the N(1), N(3), C(4), and C(5) atoms have been studied the best. 11-14 They are synthesized under conditions of both base and acid catalysis. The most widely used method of synthesis of DHIT is the base catalyzed coupling of thioureas with α dicarbonyl compounds. 12-14 Acid catalysis was em ployed in the reaction of unsymmetrically substituted α dicarbonyl compounds with thiourea or 1,3 dimethyl thiourea. 15 A few examples of the coupling of 4,5 dihydroxy imidazolidine 2 thione (1а) with ureas for the synthesis of hetero analogs of glycolurils (tetrahydroimidazo [4,5 d]imidazole 2,5 diones) were described; however, no data on the method of synthesis and on the yield and melting point of this compound are available. 16 The structure of DHIT has virtually not been discussed in the literature. 17 To develop synthetic routes to new 4,5 dihydroxyimi dazolidine 2 thiones and to perform a detailed study of their structure, in the present work we studied the cou pling of thioureas with glyoxal and analyzed the structure of reaction products by NMR spectroscopy, chtomato mass spectrometry, and X ray diffraction analysis (includ ing detailed examination of the electron density distribu tion in the crystal).The synthesis of DHIT 1а-c from glyoxal and thio ureas 2а-c (Scheme 1) was studied under the conditions similar to those reported earlier 3,18,19 for DHI. The effect of temperature (20-90 °С), reaction time (0.5 to 7.5 h), and рН of the medium (pH 3-9) on the yields of the target DHIT were investigated. It was found that com pound 1а is formed in 47-50% yield after 30 min at рН 4 and 50 °С unlike related DHI, 3 which is prepared at рН 6.5-7.5 and 90 °С. Compounds 1b,c were obtained in 75-78 and 60-63% yields, respectively, after 2 h at рН 5-6 and 50 °С analogously to 1,3 diethyl DHI, which was obtained under identical conditions, but after 7 h. 19

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Isolation and X-ray structure of the intermediate dihydroxyimidazolidine(DHI) in the synthesis of glycoluril from glyoxal and urea.

Cited by 63 publications

References 2 publications

Anion‐Free Bambus[6]uril and Its Supramolecular Properties

Anion‐Free Bambus[6]uril and Its Supramolecular Properties

A green synthesis of glycoluril derivatives in aqueous solution with recycle of the waste

The synthesis, structure, and electron density distribution in crystals of 4,5-dihydroxyimidazolidine-2-thiones

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