- A new and efficient method for the preparation of 2,4,6,8- Tetraazabicyclo[3.3.0]octane-3,7-diones (Glycolurils) catalyzed by keggin, wells-dawson, and preyssler heteropolyoxometalates, effect of structure on the reactivity
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Some important cis- and trans-alkyl substituted glycolurils were prepared via condensation of vicinal dicarbonyl compounds with urea and/or methylurea catalyzed by 0.95 mol% of Keggin- type H3PW12O 40 under environmentally benign and simple condition. Proficiency of structurally different heteropolyoxometalates, including Keggin, Wells-Dawson, and Preyssler, was investigated in the reaction of urea with 2, 3-butanedione. A common method was introduced for the isolation of cis- and trans-isomers, role of different solvents was studied, and effect of catalyst mol% was also investigated in this reported.
- Tayebee, Reza,Esmaei, Rezaei-Seresht,Behrooz, Maleki
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- Synthesis of Glycoluril using Urea Phosphate
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Abstract: Glycolurils are building blocks for the synthesis of cucurbiturils that are important host materials for several applications. Glycolurils are prepared conveniently by the condensation of 1,2-diketones with urea using an acid as catalyst. Herein, we report a facile method of synthesis of various glycolurils using urea phosphate and 1,2-diketones.
- Karpagalakshmi, K.,Lakshminarayanan, P.,Prakash, R.,Ramalakshmi, S.,Selvapalam, N.,Usha, G.,Yang, C.
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p. 1988 - 1992
(2022/01/24)
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- Synthesis of glycolurils and hydantoins by reaction of urea and 1, 2-dicarbonyl compounds using etidronic acid as a “green catalyst”
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Most of the known methods for the synthesis of heterocyclic compounds have disadvantages, such as a long reaction time and aggressive conditions. We have developed a new, rather simple and efficient method for the synthesis of a number of glycoluryls and hydantoins in water using a etidronic acid (HEDP) as “Green catalyst.” So, for the first time, the condensation reaction of ureas with 1, 2-dicarbonyl compounds was carried out in the presence of HEDP. Also based on NMR studies, a chemism of these reactions, which is stepwise, is proposed. It has been established that the optimal conditions for the synthesis of glycoluryls and hydantoins using HEDP are: temperature 80°C-90°C, 40-20 minutes, and the ratio of urea and HEDP is 1:1. In all cases, the remaining aqueous filtrate containing HEDP after the reaction can be reused for other cycles synthesis of glycoluril and other compounds, because HEDP is not converted during the reaction.
- Bakibaev, Abdigali A.,Uhov, Artur,S. Malkov, Victor,Yu. Panshina, Svetlana
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p. 4262 - 4270
(2020/10/02)
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- ACYCLIC CUCURBIT(N)URIL TYPE MOLECULAR CONTAINERS TO TREAT INTOXICATION AND DECREASE RELAPSE RATE IN SUBSTANCE ABUSE DISORDERS
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Provided are methods for reversing the effects of drugs of abuse. The method involves administering acyclic CB[n]-type compounds to a mammal in need of the reversal of the effects from a drug of abuse.
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Paragraph 0144
(2016/12/12)
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- Synthesis of some novel tetraimidazolium salts derived from diphenyl- and dimethylglycolurils
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Several new tetrabromo compounds based on diphenyl- and dimethylglycolurils were synthesized. Sequential treatment of these compounds with imidazole, methyl iodide, and sodium tetrafluoroborate gave their corresponding tetra imidazolium salts. Some of the
- Rahimizadeh, Mohammad,Seresht, Esmaeel Rezaei,Golari, Neda,Bakavoli, Mehdi
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scheme or table
p. 639 - 645
(2009/07/25)
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- Mechanistic Studies in the Chemistry of Urea. Part 8. Reactions of Urea, 1-Methylurea, and 1,3-Dimethylurea with Some Acyloins and Butane-2,3-dione (Diacetyl) in Acid Solution
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Urea and 1-methylurea react with both aromatic and aliphatic acyloins to form 4-imidazolin-2-ones but, under the same reaction conditions, 1,3-dimethylurea does not react.However, 1,3-dimethylurea does react with diacethyl to form 4,4'-methylenebis-(1,3,5-trimethyl-4-imidazolin-2-one) (4a).The carbon atom lost in the formation of (4a) is eliminated as formaldehyde.We propose a reaction mechanism which involves formation of an oxetan ring.With 1-methylurea and urea the main products of reaction with diacetyl are the bicyclic compounds (6a-c).However, it is possible that reactions analogous to that leading to the formation of (4a) also occur and that the carbonium ion (5c) is the coloured species formed in the well known colorimetric procedure for the determination of urea concentrations in biological liquids.
- Butler, Anthony R.,Hussain, Ishtiaq
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p. 310 - 316
(2007/10/02)
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