- Continuous Synthesis of Hydantoins: Intensifying the Bucherer-Bergs Reaction
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A continuous Bucherer-Bergs hydantoin synthesis utilizing intensified conditions is reported. The methodology is characterized by a two-feed flow approach to independently feed the organic substrate and the aqueous reagent solution. The increased interfacial area of the biphasic reaction mixture and the lack of headspace enabled almost quantitative conversions within ca. 30 minutes at 120 °C and 20 bar even for unpolar starting materials. In addition, a selective N(3)-monoalkylation of the resulting heterocycles under batch microwave conditions is reported yielding potential acetylcholinesterase inhibitors.
- Monteiro, Julia L.,Pieber, Bartholom?us,Corrêa, Arlene G.,Kappe, C. Oliver
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supporting information
p. 83 - 87
(2015/12/26)
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- Synthesis and in vivo hypoglycemic activity of new imidazolidine-2,4-dione derivatives
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A series of new 3-arylsulfonylimidazolidine-2,4-diones (2a-2p) were synthesized by reacting imidazolidine-2,4-diones (1a-1e) with arylsulfonyl chlorides in the presence of triethyl amine. The imidazolidine-2,4-diones (1a-1e) were in turn synthesized from the corresponding ketones through Bucherer-Bergs reaction. All the synthesized compounds were characterized on the basis of their spectral (IR, 1H and 13C NMR and MS) and microanalytical data. The hypoglycemic activity of the compounds (2a-2p) was evaluated using alloxanized diabetic rat model. Compound 2a showed an excellent activity with a reduction in the blood glucose level of -286 ± 7 mg/dL after 5 h of drug administration as compared to -270 ± 8 mg/dL for glipizide. The hypoglycemic activity of compound 2b (-268 ± 9 mg/dL) was also comparable to the standard drug. However, only moderate activity was observed for compound 2e.
- Hussain, Abid,Kashif, Muhammad Kalim,Naseer, Muhammad Moazzam,Rana, Usman A.,Hameed, Shahid
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p. 7313 - 7326
(2015/09/29)
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- Mechanochemical preparation of hydantoins from amino esters: Application to the synthesis of the antiepileptic drug phenytoin
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The eco-friendly preparation of 5- and 5,5-disubstituted hydantoins from various amino ester hydrochlorides and potassium cyanate in a planetary ball-mill is described. The one-pot/two-step protocol consisted in the formation of ureido ester intermediates, followed by a base-catalyzed cyclization to hydantoins. This easy-handling mechanochemical methodology was applied to a large variety of α- and β-amino esters, in smooth conditions, leading to hydantoins in good yields and with no need of purification steps. As an example, the methodology was applied to the "green" synthesis of the antiepileptic drug Phenytoin, with no use of any harmful organic solvent.
- Konnert, Laure,Reneaud, Benjamin,De Figueiredo, Renata Marcia,Campagne, Jean-Marc,Lamaty, Frdric,Martinez, Jean,Colacino, Evelina
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p. 10132 - 10142
(2015/02/19)
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- Fast halogenation of some N-heterocycles by means of N,N'-dihalo-5,5- dimethylhydantoin
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An instantaneous, selective and high-yielding halogenation process is reported. The method operates with imidazoles, pyrazoles, and indoles under benign reaction conditions. The developed process involves the use of N,N'-dihalo-5,5-dimethylhydantoins (halo=chlorine, bromine, iodine) as halogenation reagents that are activated by catalytic quantities of a strong Bronsted acid. Moreover, the halogenation process is switchable to produce either the mono- or di-halogenated products. Issues related to the reaction mechanism are investigated and a proposal for a reaction mechanism is disclosed.
- Sandtorv, Alexander H.,Bjorsvik, Hans-Rene
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p. 499 - 507
(2013/05/08)
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- AMIDOALKYLPIPERAZINYL DERIVATIVES FOR THE TREATMENT OF CENTRAL NERVOUS SYSTEM DISEASES
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The invention relates to novel amidoalkylpiperazinyl derivatives of tricyclic heterocyclic systems of general formula (I), wherein Z represents -NH- and X represents -S-, or Z represents -S- and X represents >C=C1 represents H or -CH3, R6 and R7 both represent H, n is an integer from 0 to 4 inclusive, G represents a cyclic amide or imide moiety, and optical isomers, geometric isomers, and pharmaceutically acceptable salts thereof. The compounds may be useful for the treatment and/or prevention of the central nervous system disorders.
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Page/Page column 29; 30
(2013/03/26)
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- Synthesis and evaluation of anti-inflammatory and antitussive activity of hydantion derivatives
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1-Methylhydantion is a compound, which was isolated from Oviductus Ranae for the first time. In our study, we found that it showed good antitussive and anti-inflammatory activity. It is also the first report which illustrates the antitussive activity of hydantion derivative. A series of hydantion derivatives were synthesized and evaluated for their anti-inflammatory and antitussive activity in vivo. The pharmacological tests showed that compounds 7a, 7c and 7d have good anti-inflammatory and antitussive activity compared to Ibuprofen and codeine. Compound 7a in particular showed two-fold stronger anti-inflammatory activity than Ibuprofen.
- Lu, Haibin,Kong, Dejuan,Wu, Bin,Wang, Shihan,Wang, Yongsheng
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experimental part
p. 638 - 642
(2012/08/28)
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- PROCESS FOR STRAIGHTENING KERATIN FIBRES WITH A HEATING MEANS AND DENATURING AGENTS
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The invention relates to a process for straightening keratin fibres, comprising: (i) a step in which a straightening composition containing at least two denaturing agents is applied to the keratin fibres, (ii) a step in which the temperature of the keratin fibres is raised, using a heating means, to a temperature of between 110 and 250° C.
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- New polyamides based on 1,3-bis(4-carboxy phenoxy) propane and hydantoin derivatives: Synthesis and properties
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Six new polyamides 5a-f containing flexible trimethylene segments in the main chain were synthesized through the direct polycondensation reaction of 1,3-bis(4-carboxy phenoxy) propane 3 with six derivatives of hydantoins 4a-f in a medium consisting of N-methyl-2-pyrrolidone, triphenyl phosphite, calcium chloride and pyridine. The polycondensation reaction produced a series of novel polyamides in high yield with inherent viscosities between 0.30-0.47 dL/g. The resulted polymers were fully characterized by means of FT-IR, 1H-NMR spectroscopy, elemental analyses, inherent viscosity, solubility tests and gel permeation chromatography (GPC). Thermal properties of these polymers were investigated by using thermal gravimetric analysis (TGA) and differential thermal gravimetry (DTG). The glass-transition temperatures of these polyamides were recorded between 130 and 155 °C by differential scanning catorimetry (DSC), and the 5% weight loss temperatures were ranging from 325 to 415 °C under nitrogen. 1,3-bis(4-Carboxy phenoxy) propane 3 was prepared from the reaction of 4-hydroxy benzoic acid 1 with 1,3-dibromo propane 2 in the presence of NaOH solution.
- Faghihi, Khalil,Valikhani, Nasim
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experimental part
p. 77 - 83
(2010/12/19)
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- 4,5-Dihydroxyimidazolidin-2-ones in the α-ureidoalkylation reaction of N-(carboxyalkyl)-, N-(hydroxyalkyl)-, and N-(aminoalkyl)ureas 1. α-Ureidoalkylation of N-(carboxyalkyl)ureas
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The α-ureidoalkylation of N-(carboxyalkyl)ureas (ureido acids) with 1,3-H2 s-, 1,3-Me 2 s-, and 1,3-Et2 s-4,5-dihydroxyimidazolidin-2-ones was systematically studied. The yields of glycolur
- Kravchenko,Lyssenko,Chikunov,Belyakov,Il'In,Baranov,Nelyubina,Davankov,Pivina,Makhova,Antipin
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experimental part
p. 395 - 405
(2010/07/08)
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- Facile one-pot synthesis of 5-substituted hydantoins
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5-Substituted and 5,5-disubstituted hydantoins are synthesised from the corresponding aldehydes or ketones, using a one-pot, gallium(iii) triflate-catalysed procedure that is compatible with a range of substrates and solvents.
- Murray, Ross G.,Whitehead, David M.,Le Strat, Franck,Conway, Stuart J.
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scheme or table
p. 988 - 991
(2009/02/05)
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- Process for producing N-halogenated organic compounds
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The process enables highly effective N-halogenation of a compound having one or more halogenatable amido or imido functional groups in the molecule. The process involves, for example, concurrently feeding into a reactor (i) water, inorganic base, and the compound to be N-halogenated, e.g., a hydantoin, and a feed of (ii) a brominating agent and/or a chlorinating agent. The proportions of these feeds are such that the pH is kept at 5 or below or within a specified range e.g., 5.5-8.5 and one or more of the amido or imido nitrogen atoms is substituted by a bromine or chlorine atom. A feature of the process is that it can be conducted at elevated temperatures as high as about 90° C. without appreciable thermal decomposition of reactants or product. The resultant product continuously precipitates in high yield and purity. Moreover, products can be produced that are very pale yellow to almost pure white in appearance. Further, the process has been found capable of producing 1,3-dibromo-5,5-dimethylhydantoin with far larger particle sizes than previously produced on a commercial basis.
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- APPLICATION OF THE BUCHERER REACTION TO CARBOHYDRATE DERIVATIVES
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The Bucerer reaction of carbohydrate derivatives having a free carbonyl group proceeds normally, giving mainly the expected spiro-hydantoin derivatives.With derivatives having a free aldehydo group attached to an acetal ring in an α-position, the acetal ring is opened via an elimination reaction yielding unsaturated hydantoin derivatives.These reactions were studied using 1,2:5,6-di-O-isopropylidene-α-D-ribo-hexofuranos-3-ulose, 2,3:4,5-di-O-isopropylidene-D-arabinose, -D-ribose, and -D-xylose, 2,3:5,6-di-O-isopropylidene-α-D-mannofuranose, 1,2-O-isopropylidene-3-O-methyl-α-D-xylo-pentodialdo-1,4-mannofuranose, 1,2:3,4-di-O-isopropylidene-α-D-galacto-hexodialdo-1,5-pyranose, and 2,3:4,5-di-O-isopropylidene-β-D-arabino-hexosulo-2,6-pyranose.
- Kuszmann, Jaanos,Maatron-Mereesz, Magdolna,Jerkovich, Gyula
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p. 249 - 264
(2007/10/02)
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- Soil disease-controlling imides
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A soil disease controlling agent for preventing and controlling diseases caused by pathogenic fungi living in soil, which comprises an effective amount of at least one of a 2-cycloalkenylamine derivative and its salts as an active ingredient, and at least one inert carrier or diluent.
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- REACTION OF N-HALOGENOIMIDES WITH SULFUR. THIODIIMIDES
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The reaction of N-halogenoimides with sulfur leads to the production of thiodiimides.The latter are active sulfur-transferring reagents.
- Borovikova, G.S.,Levchenko, E.S.,Kaminskaya, E.I.
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- Potentiometric Determination using Bromochlorohydantoin as a New Oxidimetric Titrant
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A new oxidimetric titrant, bromochlorohydantoin (1-bromo-3-chloro-5,5-dimethylhydantoin) is introduced for use in non-aqueous media.Direct potentiometric determinations of a variety of diverse types of reductants, viz. arsenic(III), antimony(III), tin(II), iron(II), thallium(I), ferrocyanide, iodide, hydrazine, phenylhydrazine, semicarbazide, hydroquinone, aniline, ascorbic acid, oxine, thiosulphate, thiourea thiosemicarbazide, thiocyanate, Reinecke's salt, mercury(II) tetrathiocyanatocobaltate(II) and mercury(II) tetrathiocyanatozincate(II) have been carried out using this titrant.
- Indrasenan, P.,Radhamma, M. P.
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p. 729 - 730
(2007/10/02)
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- Process for the preparation of active-type vitamin D3 compounds
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The present invention relates to a novel process for the preparation of active-type vitamin D3 compounds and their intermediates. In accordance with the present invention, a large amount of an active-type vitamin D3 compounds, for example 1α-hydroxycholecalciferol, 1α,25-dihydroxycholecalciferol and the like, is efficiently prepared with high industrial advantages by a novel processes, which comprises (i) reacting hydroxycholesta-5-enes having the hydroxyl groups protected with lower alkoxycarbonyl group as a starting material with allylic brominating agent and dehydrobrominating agent to prepare the corresponding hydroxycholesta-5,7-dienes, (ii) exposing the hydroxycholesta-5,7-dienes to ultraviolet irradiation or to a combination of the irradiation with thermal isomerization to obtain a mixture of the unreacted hydroxycholesta-5,7-dienes and previtamin D3 compounds or a mixture of the unreacted hydroxycholesta-5,7-dienes and the protected active-type vitamin D3 compounds, (iii) separating the mixture into the unreacted hydroxycholesta-5,7-dienes and previtamin D3 compounds or the protected active-type vitamin D3 compounds, (iv) recycling the unreacted hydroxycholesta-5,7-dienes as reuse and (v) thermally isomerizing the remaining compounds and/or splitting off the protective groups. The process for the preparation of active-type vitamin D3 compounds, in the present invention, is of very high industrial value, capable of carrying out by simple operation and adaptable to large scale commercial production.
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- Novel 1α,24-dihydroxycholecalciferol compositions, novel precursors thereof, and processes for preparing them
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Novel 1α, 24-dihydroxycholecalciferol and derivatives thereof which are useful with reduced side-effects for the treatment of abnormal metabolism of calcium and phosphorus caused by liver failure, renal failure, gastrointestinal tract failure and parathyroid failure, and related bone diseases. Preparation of the novel 1α, 24-dihydroxycholecalciferol and their derivatives starts from 1α, 24-dihydroxycholesterol prepared by reacting 1α, 2α-epoxy-24-keto-cholesta-4,6-dien-3-one with an alkali metal and a proton donor in the presence of liquid ammonia or a liquid amine. Reaction of the 1α, 24-dihydroxycholesterol with an allylic brominating agent, followed by contacting with a dehydrobrominating agent, affords 1α,3β, 24-trihydroxycholesta-5,7-diene derivative, which can then be converted to 1α, 24-dihydroxycholocalciferol by ultraviolet irradiation in a organic solvent, followed by isomerization. Processes are also provided for separating 1α, 24-dihydroxycholesterol into an (S)-epimer and an (R)-epimer, and also for separating at least one of 1α, 3β, 24(S)-and 1α, 3β, 24(R)-trihydroxycholesta-5,7-dienes from trihydroxycholesta-4,6-diene.
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