- INFRARED STUDY OF THE ADSORPTION OF ETHYL ISOCYANATE ON SILICA IMMERSED IN TETRACHLORIDE
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Infrared spectra are reported of silica immersed in solutions of ethyl isocyanate in carbon tetrachloride.Interactions between surface silanol groups and ethyl isocyanate led to the formation of a surface urethane, ethylamine and 1,3-diethylurea as the products of adsorption.Increasing hydroxyl population of the silica surface enhanced the formation of 1,3-diethylurea but diminished the extent of reaction of isolated silanol groups to give urethane.Adsorbed ethylammonium ions were produced by proton transfer from silanol groups to ethylamine molecules at the solid/liquid interface.The results are discussed in relation to previous spectroscopic data for the adsorption of ethyl isocyanate on silica at the solid/vapour interface.
- Cross, Stephen N. W.,Rochester, Colin H.
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Read Online
- CARBONATE DERIVATIVE PRODUCTION METHOD
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The objective of the present invention is to provide a method for producing a carbonate derivative in a safe and efficient manner. The method for producing a carbonate derivative according to the present invention is characterized in comprising irradiating light on a composition containing a C1-4 halogenated hydrocarbon having one or more kinds of halogen atoms selected from the group consisting of a chlorine atom, a bromine atom and an iodine atom, a nucleophilic functional group-containing compound and the specific base in the presence of oxygen.
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Paragraph 0153-0154; 0161-0162
(2020/04/09)
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- PROCESS FOR PREPARING CYCLIC ALKYLENE UREAS
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A process for producing a cyclic alkylene urea product of Formula I: in which a compound of Formula II and/or Formula III is contacted in a reaction zone with a compound of Formula IV and/or Formula V and in the presence of one or more carbonyl delivering compounds; in which; R1 is –[A?X?]qR3; R2 is on each occurrence independently selected from H and C1 to C6 alkyl groups which are optionally substituted by one or two groups selected from ?OH and ?NH2; R3 is on each occurrence independently selected from H and C1 to C6 alkyl groups which are optionally substituted by one or two groups selected from ?OH and ?NH2; A is on each occurrence independently selected from C1 to C3 alkylene units, optionally substituted by one or more C1 to C3 alkyl groups; X is on each occurrence independently selected from ?O?, ?NR2?, groups of Formula VI, and groups of Formula VII and p and q are each independently selected from a whole number in the range of from 0 to 8; wherein the compound of Formula II and/or the compound of Formula III are added to a reaction zone comprising compound of Formula IV and/or compound of Formula (V) continuously or semi-continuously over a period of time, or in two or more batches.
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Page/Page column 14; 16-17
(2019/02/25)
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- Synthesis, thermolysis, photolysis and antimicrobial evaluation of some novel semicarbazones and thiosemicarbazones derived from 3-methyl-2-benzothiazolinone hydrazone
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REACTION of 3-methyl-2-benzothiazolinone hydrazone (1) with?? some selected isocyanate and isothiocyanate reagents 2a-j gave the respective semicarbazones and thiosemicarbazones 3a-j. Thermolysis of compound 3a under reduced pressure gave N,N'-diethylurea (4) in addition to 1,2-bis(3-methylbenzo[d]thiazol-2(3H)-ylidene)hydrazine (5). Compound 3a was almost quantitatively recovered upon its exposure to sunlight in methanol for 60 days. Elementary and spectroscopic measurements (IR, 1H NMR, 13C NMR, MS) are in good accord with the structures postulated for the new compounds. The single crystal X-ray crystallographic analysis of 3f was given and its data were discussed. The synthesized compounds 3aj as well as the hydrazone 1 were screened for their antibacterial properties against Bacillus subtilis (G+), Escherichia coli (G-), Pseudomonas aeruginosa (G-) and Staphylococcus aureus (G+) and for their antifungal properties against Aspergillus flavus and Candida albicans. Some of the tested compounds showed an activity against the four bacterial strains where their order of activity was found to be 1 > 3g > 3j > 3i > 3e > 3h > 3a. The MIC90 value of compound 1 against P. aeruginosa was 9 mg/ml. On the other hand only compound 1 showed a significant activity against A. flavus fungal species where it recorded an inhibition zone diameter value (16 mm/mg) which is very near to that of the standard drug, amphotericin B (17 mm/mg). However, the C. albicans was found to be insensitive to all of the investigated compounds.
- Yosef, Hisham Abdallah A.,Ibrahim, Nabila M.
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p. 867 - 886
(2017/04/17)
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- Three-component reaction between imidazoles, isocyanates, and cyanophenylacetylene: A short-cut to N-(Z)-alkenylimidazole-2-carboxamides
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1-Substituted imidazoles, isocyanates, and cyanophenylacetylene react under mild (rt), non-catalytic solvent-free conditions to give (Z)-(2-cyano-1- phenylethenyl)imidazole-2-carboxamides in up to 72% yields and with ca. 100% stereoselectivity. The reaction starts from the initial formation of zwitterion/carbene intermediates captured by the isocyanate as the electrophile followed by migration of the alkenyl moiety from the N-3 atom to the anionic center at the carboxamide nitrogen. Thus, the reaction provides an easy access to a novel family of functionalized imidazoles.
- Belyaeva, Kseniya V.,Andriyankova, Ludmila V.,Nikitina, Lina P.,Mal'Kina, Anastasiya G.,Afonin, Andrei V.,Trofimov, Boris A.
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supporting information
p. 7040 - 7043
(2013/01/15)
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- Microwave-assisted synthesis of symmetrical and unsymmetrical N,N 0-disubstituted thioureas and ureas over MgO in dry media
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Under mild microwave irradiation conditions a variety of symmetrical and unsymmetrical A,N′-disubsti-tuted thioureas and ureas were prepared via the reaction of Af-monosubstituted hydroxylamines with isocyanate and isothiocyanate derivatives over MgO under solvent-free conditions. This new method afforded satisfactory results with good yields, short reaction time, and simplicity in the experimental procedure.
- Valizadeh, Hassan,Dinparast, Leila
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experimental part
p. 251 - 254
(2012/07/01)
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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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- 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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body text
p. 395 - 405
(2010/07/08)
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- Preparation of mono-, di-, and trisubstituted ureas by carbonylation of aliphatic amines with S,S-dimethyl dithiocarbonate
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General procedures are reported to prepare N-alkylureas, N,N′-dialkylureas (both symmetrical and unsymmetrical), and N,N,N′-trialkylureas by carbonylation of aliphatic amines, employing S,S-dimethyl dithiocarbonate (DMDTC) as a phosgene substitute. All reactions were carried out in water. Symmetrical disubstituted ureas were prepared directly working at 60°C with a molar ratio of DMDTC:amine = 1:2, preferably under nitrogen. Unsymmetrical ureas were prepared in two steps via S-methyl N-alkyl-thiocarbamate intermediates, which are formed selectively in the first step at room temperature. These intermediates react in the second step with ammonia or various aliphatic amines, both primary and secondary, at temperatures varying between 50 and 70°C. All the target ureas were obtained in high yields (28 examples, average yield 94%) and with very high purity (generally >99.2%). Also to be noted is the recovery of a co-product of industrial interest, methanethiol, in an amount of two moles for each mole of DMDTC, with complete exploitation of the reagent. Georg Thieme Verlag Stuttgart.
- Artuso, Emma,Degani, Iacopo,Fochi, Rita,Magistris, Claudio
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p. 3497 - 3506
(2008/09/19)
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- CeCl3 · 7H2O-KI-catalyzed, environmentally friendly synthesis of N,N′-disubstituted ureas in water under microwave irradiation
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N,N′-Disubstituted ureas were efficiently synthesized by reactions of urea with a variety of amines in water under microwave irradiation using CeCl3 · 7H2O-KI as catalyst. This protocol has advantages of not using toxic phosgene and hazardous organic solvents, high reaction rate, high yield, and a simple workup procedure. Copyright Taylor & Francis, Inc.
- Li, Zheng
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p. 2325 - 2331
(2007/10/03)
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- Expeditious method for synthesis of symmetrical 1,3-disubstituted ureas and thioureas
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Symmetrical 1,3-disubstituted ureas and symmetrical thioureas have been synthesized from corresponding isocyanates, diisocyanates, and isothiocyanates by a new versatile, simple, and quick method in the presence of tertiary amines at room temperature. The method under discussion has several advantages over the existing techniques, as it is simple to carry out, does not require complicated equipment, has a simple workup, and does not use expensive chemicals. Moreover, the yields are almost quantitative. This method has potential in commercial applications. Copyright Taylor & Francis, Inc.
- Perveen, Shahnaz,Abdul Hai, Syed M.,Khan, Rashid A.,Khan, Khalid Mohammed,Afza, Nighat,Sarfaraz, Tahira B.
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p. 1663 - 1674
(2007/10/03)
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- Process to prepare alkyl-ureas from O,S-dimethyl dithiocarbonate
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The present invention relates to the preparation of alkyl-ureas, starting from O,S-dimethyl dithiocarbonate, which provides the following steps: A) causing the O,S-dimethyl dithiocarbonate to react with a primary amine of general formula R1NH2in order to obtain an O-methyl thiocarbamate; B) isomerising the O-methyl thiocarbamate in order to obtain an S-methyl thiocarbamate; C) causing the S-methyl thiocarbamate with a compound of general formula R′R″NH, wherein R′ and R″ may be equal or different one in respect of the other and of R1and may be H, R2or R3, in order to obtain one of the alkyl-ureas of formula (4), (5) or (6).
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Page column 9
(2010/02/06)
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- Process to prepare alkyl-ureas from O,S-dimethyl dithiocarbonate
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The present invention relates to the preparation of alkyl-ureas, starting from O,S-dimethyl dithiocarbonate, which provides the following steps:A) causing the O,S-dimethyl dithiocarbonate to react with a primary amine of general formula R1NH2 in order to obtain an O-methyl thiocarbamate;B) isomerising the O-methyl thiocarbamate in order to obtain an S-methyl thiocarbamate;C) causing the S-methyl thiocarbamate with a compound of general formula R'R"NH, wherein R' and R" may be equal or different one in respect of the other and of R1 and may be H, R2 or R3, in order to obtain one of the alkyl-ureas of formula (4), (5) or (6).
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- Palladium-catalyzed azathiolation of carbon monoxide
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A novel palladium-catalyzed azathiolation of carbon monoxide using sulfenamide (RSNR'2) (1) is described to provide thiocarbamate 2 in good yields. The mechanistic proposal includes the following: (1) insertion of CO into Pd-S bond of Pd(SR)2(PPh3)(n) 4 to provide Pd[C(O)SR](SR)(PPh3)(n) 5 and (2) σ-bond metathesis between S-N and Pd-C(O) bonds to afford 2 with the regeneration of 4.
- Kuniyasu, Hitoshi,Hiraike, Hiroshi,Morita, Masaki,Tanaka, Aoi,Sugoh, Kunihiko,Kurosawa, Hideo
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p. 7305 - 7308
(2007/10/05)
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- Palladium-Catalyzed Double and Single Carbonylations of β-Amino Alcohols. Selective Synthesis of Morpholine-2,3-diones and Oxazolidin-2-ones and Applications for Synthesis of α-Oxo Carboxylic Acids
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Catalytic cross double carbonylation of secondary amines and alcohols proceeds in the presence of [PdCl2(MeCN)2] and CuI under carbon monoxide (80 atm) and oxygen (5 atm). Catalytic intramolecular double carbonylation of β-amino alcohols gives morpholine-2,3-diones, which are excellent protecting compounds of amino alcohols and important precursors for biologically active nitrogen compounds. In contrast, catalytic single carbonylation of β-amino alcohols under a mixture (1 : 1) of carbon monoxide and oxygen (1.0 atm) proceeds to give oxazolidin-2-ones selectively. The reaction can be explained by assuming a mechanism which includes intramolecular nucleophilic attack of the hydroxy group of (hydroxyethyl)aminocarbonyl ligands on the CO ligand of the carbamoylpalladium(II) complexes, followed by reductive elimination to give morpholine-2,3-diones. In contrast, direct nucleophilic attack of the hydroxy group to the carbamoyl group affords oxazolidin-2-ones. As a common intermediate for the double and single carbonylations, carbamoylpalladium(II) complex has been isolated by the reaction of [PdCl2(PMe3)2] with β-amino alcohol under CO. The present double carbonylation of amino alcohols provides a novel and convenient method for synthesis of α-oxo carboxylic acids. Thus, the morpholine-2,3-diones obtained undergo reaction with Grignard reagents chemoselectively at the ester positions to give 2-substituted 2-hydroxymorpholin-3-ones, which undergo acid hydrolysis to give α-oxo carboxylic acids.
- Imada, Yasushi,Mitsue, Yo,Ike, Kazuo,Washizuka, Ken-Ichi,Murahashi, Shun-Ichi
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p. 2079 - 2090
(2007/10/03)
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- Preparation, characterization, and reactions of 16-electron Ta(η5-C5Me5)(η3-1-phenylallyl)2
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Treatment of Cp*TaCl4 with 4 equiv of phenylallylMgBr in THF afforded Cp*Ta(1-phenylallyl)2 (2), whose structure was characterized by a single crystal X-ray study as 16-electron two legged piano stool with two allyl moieties in supine-supine geometry.In this reaction, the starting TaV complex was reduced to a TaIII species accompanying the formation of reductive allyl-coupling products, diphenyl-1,5-hexadiene derivatives 3. ?-Donor molecules such as carbon monoxide, tert-butyl isocyanide, isocyanates and isothiocyanates induced the coupling reaction of two phenylallyl groups on tantalum to give 1,6-diphenyl-1,5-hexadiene (3a).The intermediate Cp*Ta(tert-BuNC)2(η2,η2-1,6-diphenyl-1,5-hexadiene) (5) was characterized by 1H NMR spectroscopy.Complex 2 was the catalyst precursor for the selective dimerization of isocyanates.Oxygen donor molecules such as DMSO and pyridine-N-oxide reacted with 2 to afford 1:1 adducts.One-electron oxidation of 2 with ferrocenium cation resulted in the formation of 1-phenyl-1-propene.The TaIV complexes, *Ta(1-phenylallyl)2>, were obtained by the reaction of 2 with TCNQ and DDQ.
- Mashima, Kazushi,Yamanaka, Yoshimichi,Gohro, Yoshihiko,Nakamura, Akira
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p. 131 - 138
(2007/10/02)
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- Oxidative coupling of amines and carbon monoxide catalyzed by palladium complexes. Mono- and double carbonylation reactions promoted by iodine compounds.
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Iodine is an effective promoter for the carbonylation of primary and secondary amines to ureas using palladium acetate as the catalyst and a base (e.g.K2CO3) in acetonitrile (3 h at 95 deg C and 2.7 atm).Oxamides are formed in excellent yields when secondary amines are carbonylated in the presence of iodide ion and oxygen, while primary amines give ureas as the principal product at 95 deg C, and oxamide at room temperature.
- Pri-Bar, Ilan,Alper, Howard
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p. 1544 - 1547
(2007/10/02)
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- ELECTROCHEMICAL ACYLATION AND ALKYLAMINOCARBONYLATION OF AMINES AND ALCOHOLS
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Electrochemical acylation and ethylaminocarbonylation of amines and alcohols are performed by anodic oxydation of the hydroxamic acids and N-ethyl-N'-hydroxyurea, respectively, in acetonitrile at a glassy-carbon electrode.
- Masui, Masaichiro,Ozaki, Shigeko
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p. 2867 - 2870
(2007/10/02)
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- PERCARBAMATE DE t-BUTYLE ET SES DERIVES N-ALKYLES, N,N-DIALKYLES ET N-AZACYCLANIQUES: PREPARATION ET THERMOLYSE EN SOLUTION
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Several tert-butyl percarbamates have been prepared by the reaction of amines with tert-butyl imidazoylpercarboxylate.The thermal decomposition of these peresters in solution led to the characteristic products of homolytic processes.The kinetic study of the thermolysis has been performed by Differential Scanning Microcalorimetry.It showed the influence of the nitrogen atom substitution on the percarbamate stability.The kinetic study of the decompositions of percarbamates derived from cyclic amines showed an important effect of the cycle size on the rate constant.Very different transition state levels are responsible for this phenomenon.A stereoelectronic origin-from the overlapping of the p-orbital of the nitrogen atom and the ? bond of the carboxyl- has been advanced to account for this result.
- Buorgeois, M. J.,Campagnole, M.,Filliatre, C.,Maillard, B.,Manigand, C.,et al.
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p. 3569 - 3577
(2007/10/02)
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- Synthesis of Nitrosothioureas. 15N N.M.R. Evidence for the Formation of Thionitrosyl Compounds in the Nitrosation of Thioureas
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Nitrosothioureas may be prepared by treatment of thioureas with NaNO2 in 0.1 N HCl at -5 deg C by direct N-nitrosation whereas 15N n.m.r. studies at -10 deg C which employed specifically 15N-enriched compounds revealed the intermediacy of a thionitrosyl compound under more acidic conditions which gave the urea by hydrolysis.
- Lown, J. William,Chauhan, Shive M. S.
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p. 675 - 676
(2007/10/02)
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- Application of 15N Spectroscopy and Dynamic NMR to the Study of Ureas, Thioureas and their Lewis Acid Adducts
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Rotational barriers and 15N chemical shifts have been measured in a number of ureas and thioureas.As anticipated on the basis of the 15N shifts, several previosly unobserved rotational barriers could be detected by using lanthanide reatgents or a high field spectometer.Nearly constant effects on both the rotational activation energy and the 15N shift are produced on going from ureas to the corresponding thioureas, and correlations are found between the ΔG(ex. cit) and ?15N values.The results are discussed in terms of lone pair delocalization, and anomalies with respect to general behaviour are tentatively explained in the light of the effect of steric torsion in crowded structures on the 15N shifts and rotation barriers.
- Martin, M. L.,Filleux-Blanchard, M. L.,Martin, G. J.,Webb, G. A.
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p. 396 - 402
(2007/10/02)
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- Oxidation of Hydroxylamine Derivatives. Part 5. Anodic Oxidation of N-Hydroxy- and N-Alkoxy-ureas
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The anodic oxidation of the ureas EtNH.CO.NR1OR2 (1)-(5) has been studied by cyclic voltammetry and controlled potential electrolysis in acetonitrile at a glassy carbon electrode.The products of oxidation suggest that (1)-(3) result in cleavage between the carbon of the ethylaminocarbonyl group and the nitrogen of the hydroxylamino-group.Part of the intermediate radical of (3) undergoes disproportionation rather than cleavage of the carbon-nitrogen bond.In the case of (4) and (5), the cleavage of the carbon-nitrogen bond as observed in (1)-(3) is the main reaction route, but the possibility of N-N coupling of the intermediate followed by intramolecular rearrangement cannot be neglected.Oxidations were carried out in both divided and undivided cells.
- Ozaki, Shigeko,Masui, Masaichiro
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p. 1022 - 1027
(2007/10/02)
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