- Comparing hydrazine-derived reactive groups as inhibitors of quinone-dependent amine oxidases
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Lysyl oxidase has emerged as an important enzyme in cancer metastasis. Its activity has been reported to become upregulated in several types of cancer, and blocking its activity has been shown to limit the metastatic potential of various cancers. The small-molecules phenylhydrazine and β-aminopropionitrile are known to inhibit lysyl oxidase; however, issues of stability, toxicity, and poorly defined mechanisms limit their potential use in medical applications. The experiments presented herein evaluate three other families of hydrazine-derived compounds–hydrazides, alkyl hydrazines, and semicarbazides–as irreversible inhibitors of lysyl oxidase including determining the kinetic parameters and comparing the inhibition selectivities for lysyl oxidase against the topaquinone-containing diamine oxidase from lentil seedlings. The results suggest that the hydrazide group may be a useful core functionality that can be developed into potent and selective inhibitors of lysyl oxidase and eventually find application in cancer metastasis research.
- Burke, Ashley A.,Severson, Elizabeth S.,Mool, Shreya,Solares Bucaro, Maria J.,Greenaway, Frederick T.,Jakobsche, Charles E.
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Read Online
- A Mitsunobu-based procedure for the preparation of alkyl and hindered aryl isocyanates from primary amines and carbon dioxide under mild conditions
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A Mitsunobu-based procedure for the preparation of alkyl and hindered aryl isocyanates in excellent yields from primary amines and carbon dioxide under very mild conditions is described.
- Horvath,Saylik,Elmes,Jackson,Lovel,Moody
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Read Online
- Trifluoroacetic anhydride-catalyzed oxidation of isonitriles by DMSO: A rapid, convenient synthesis of isocyanates
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A smooth and efficient oxidation of isonitriles to isocyanates by sulfoxides is catalyzed by trifluoroacetic anhydride. With use of DMSO as the oxidant and 5 mol·% TFAA (dichloromethane, -60 to 0 °C), the process is complete in a few minutes, forming dimethyl sulfide as the only byproduct. The newly formed isocyanates may be used directly or isolated in high purity by solvent evaporation.
- Le, Hoang V.,Ganem, Bruce
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Read Online
- METHOD FOR PRODUCING CARBON DIOXIDE DERIVATIVE
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PROBLEM TO BE SOLVED: To provide a method for producing a useful carbon dioxide derivative from carbon dioxide with low energy. SOLUTION: An amine is caused to absorb carbon dioxide, and without separating the carbon dioxide, it is then reacted with an acid catalyst and an olefin, thereby producing a carbon dioxide derivative, which serves as a raw material for polyurethane. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
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Paragraph 0033-0034; 0037
(2021/06/25)
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- Practical one-pot amidation of N -Alloc-, N -Boc-, and N -Cbz protected amines under mild conditions
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A facile one-pot synthesis of amides from N-Alloc-, N-Boc-, and N-Cbz-protected amines has been described. The reactions involve the use of isocyanate intermediates, which are generated in situ in the presence of 2-chloropyridine and trifluoromethanesulfonyl anhydride, to react with Grignard reagents to produce the corresponding amides. Using this reaction protocol, a variety of N-Alloc-, N-Boc-, and N-Cbz-protected aliphatic amines and aryl amines were efficiently converted to amides with high yields. This method is highly effective for the synthesis of amides and offers a promising approach for facile amidation.
- Hong, Wan Pyo,Tran, Van Hieu,Kim, Hee-Kwon
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p. 15890 - 15895
(2021/05/19)
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- Synthetic method for n-butyl isocyanate
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The invention discloses a synthetic method for n-butyl isocyanate. The method comprises the following steps: selecting n-butylcarbamyl chloride, performing a reaction in an organic solvent for 8-15 hunder catalysis of a catalyst at a temperature of 80-160 DEG C, and performing thermal decomposition to obtain the n-butyl isocyanate, wherein the reaction equation is shown in the description. According to the synthetic method for the n-butyl isocyanate provided by the invention, the n-butylcarbamyl chloride is directly subjected to the reaction in the inert solvent to obtain the n-butyl isocyanate, and the chemical synthesis method eliminates safety hazards from a process source, and is a preparation method having a reasonable process, safe production, a high reaction yield, low production costs and substantially no three waste (waste water, waste gas and industrial residue) for the n-butyl isocyanate; and the method has an advanced technological route, avoids highly toxic phosgene and diphosgene, and has simple and safe operation, a high reaction yield, low production costs, less three waste (waste water, waste gas and industrial residue), larger implementation values and social andeconomic benefits.
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Paragraph 0030-0033
(2019/10/01)
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- Ebsulfur as a potent scaffold for inhibition and labelling of New Delhi metallo-β-lactamase-1 in vitro and in vivo
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The superbug infection caused by New Delhi metallo-β-lactamase (NDM-1) has grown into an emerging threat, labelling and inhibition of NDM-1 has proven challenging due to its shuttling between pathogenic bacteria. Here, we report a potent covalent scaffold, ebsulfur, for targeting the protein in vitro and in vivo. Enzymatic kinetic study indicated that eighteen ebsulfurs gained except 1a–b and 1f inhibited NDM-1, exhibiting an IC50 value ranging of 0.16–9 μM, and 1g was found to be the best, dose- and time-dependent inhibitor with an IC50 of 0.16 μM. Also, these ebsulfurs effectively restored the antibacterial activity of cefazolin against E. coli expressing NDM-1, and the best effect was observed to be from 1g, 1i and 1n, resulting in an 256-fold reduction in MIC of the antibiotic at a dose of 16 μg/mL. The equilibrium dialysis study implied that the ebsulfur disrupted the coordination of one Zn(II) ion at active site of NDM-1. Labelling of NDM-1 using a constructed fluorescent ebsulfur Ebs-R suggested that the inhibitor covalently bound to the target through SDS-PAGE analysis in vitro. Also, labelling NDM-1 in living E. coli cells with Ebs-R by confocal microscopic imaging showed the real-time distribution change process of intracellular recombinant protein NDM-1. Moreover, the cytotoxicity of these ebsulfurs against L929 mouse fibroblastic cells was tested, and their capability to restore antibacterial activity of antibiotic against clinical strains E. coli EC08 producing NDM-1 was determined. The ebsulfur scaffold proposed here is valuable for development of the covalent irreversible inhibitors of NDM-1, and also for labelling the target in vitro and in vivo.
- Su, Jianpeng,Liu, Jiayun,Chen, Cheng,Zhang, Yuejuan,Yang, Kewu
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supporting information
p. 192 - 201
(2018/12/02)
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- Amide compound, pharmaceutical composition, preparation method and application thereof
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The invention provides an amide compound, a pharmaceutical composition, a preparation method and application thereof and belongs to the field of medicine. Structure of the amide compound is shown as aformula I. The preparation method includes: in an alkaline condition and in an organic solvent, allowing a compound I and a compound II to be in condensation reaction. The amide compound or pharmaceutically acceptable salt thereof have long-acting sensory and/or motion blocking activity, can be used for preparing long-acting local anesthetic or analgesic and is long in efficacy lasting time, little side effect and high in medication safety.
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Paragraph 0099-0102
(2018/09/11)
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- Method for synthesizing n-butyl isocyanate
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The invention discloses a method for synthesizing n-butyl isocyanate. The method comprises the following steps: weighing n-valeric acid and thionyl chloride according to the mole ratio of 1: 1, putting n-valeric acid and thionyl chloride in a round-bottomed flask, enabling an opening of the round-bottomed flask to be connected to a reflux condensing tube, of which an upper opening is provided with a calcium chloride drying tube, carrying out magnetic stirring, heating the round-bottomed flask to the temperature of 60-70 DEG C in oil bath, and carrying out reaction for 4-5 hours, so as to obtain a n-valeryl chloride crude product; and dissolving the crude product and a catalyst in an anhydrous toluene solvent, heating the solution to the temperature of 60-80 DEG C in a three-necked flask, enabling the three-necked flask to be connected to a thermometer, a reflux condensing tube, of which an upper opening is provided with a calcium chloride drying tube, and a flask cork respectively, carrying out magnetic stirring for 5-8 minutes, then, slowly adding drying sodium azide, of which the mole is equal to that of n-valeric acid, carrying out reaction until no gas is produced, keeping the reaction for 10-15 minutes, then, filtering out insolubles, and carrying out rotary evaporation to remove toluene, thereby obtaining n-butyl isocyanate. The method has the advantages of high yield, mild reaction conditions, simplicity in operation, short reaction time and little environmental pollution.
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Paragraph 0021
(2016/10/07)
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- Enantioselective synthesis of 3,5-disubstituted thiohydantoins and hydantoins
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A mild method to convert optically pure amino acid thiourea and urea derivatives to thiohydantoins and hydantoins, respectively, is described. It provides an efficient way to realize enantioselective synthesis of thiohydantoins and hydantoins with good to high isolated yields and enantiomeric purities. We found that the enantiomeric purities were highly dependent on the reaction conditions including bases, solvents, and temperature.
- Chen, Yu,Su, Li,Yang, Xinying,Pan, Wenyan,Fang, Hao
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p. 9234 - 9239
(2015/11/27)
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- Synthesis of new coumarin compounds and its hypoglycemic activity and structure-activity relationship
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Novel coumarin compounds were designed and synthesized by combining the active moieties of hypoglycemic drugs. The coumarin compounds were made by sulfanilamide with isocynate, the intermediate sulfanilamide was formed from coumarin by chlorosulfonated and aminated. These targeted compounds were characterized by FT-IR, 1H NMR and MS spectra and their hypoglycemic activities were evaluated in mice. The preliminary results showed that some compounds exhibited evident hypoglycemic effect (P > 0.01, CMC-Na as negative control). The relationship between these compounds structure with their hypoglycemic activities were studied in order to design new antidiabetic agents.
- Qi, Gang,Zhang, Wenguo
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p. 9835 - 9839
(2014/01/06)
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- Flash vacuum pyrolysis of 1,2,5-oxadiazole 2-oxides and 1,2,3-triazole 1-oxides
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The flash vacuum pyrolysis (FVP, 450-600 °C/10-3 mmHg) of 3,4-diaryl- and 3,4-dialkyl-1,2,5-oxadiazole 2-oxides (furoxans) has been investigated. In all cases the 1,2,5-oxadiazole ring cleaved cleanly at O(1)-N(2) and C(3)-C(4) to afford two nitrile oxide fragments, which were trapped in high yield (75-97%) as their isoxazoline cycloadducts by reaction with alk-1-enes. At higher temperatures (700-800 °C) isocyanates were formed as by-products. The dimerisation of acetonitrile oxide to dimethylfuroxan was followed by 1H NMR spectroscopy, and the rate constant for the 2 nd order reaction determined. The furoxans were converted into isocyanates in good yield (61-95%) by FVP, followed by sulfur dioxide-mediated isomerisation of the resulting nitrile oxides. 2,4,5-Trisubstituted-1,2,3- triazole 1-oxides showed greater thermal stability, but at 700-800 °C decomposition of the 4,5-dimethyl compound 25b lead to 1,2-di(5-methyl-2-phenyl- 1,2,3-triazol-2-yl)ethane as the major product; attempts to trap acetonitrile oxide were unsuccessful. ARKAT USA, Inc.
- Mitchell, William R.,Paton, R. Michael
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experimental part
p. 34 - 54
(2011/02/21)
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- Synthesis and evaluation of structurally constrained imidazolidin derivatives as potent dipeptidyl peptidase IV inhibitors
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To find potent and selective inhibitors of dipeptidyl peptidase IV (DPP-IV), we synthesized a series of 2-cyanopyrrolidine derivatives with constrained imidazolidin ring and tested their activities against DPP-IV. Most of them exhibited submicromolar inhibitory activities against DPP-IV. The most potent compound among these is (S)-1-(2-(2-(3-(3,4-dimethoxyphenyl)-2-oxoimidazolidin-1-yl)ethyl-amino)acetyl)pyrrolidine-2-carbonitrile (6n), which is a 2 nM DPP-IV inhibitor.
- Wang, Liutang,Zhang, Bin,Ji, Jianxin,Li, Bogang,Yan, Jufang,Zhang, Weiyu,Wu, Yong,Wang, Xuechao
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experimental part
p. 3318 - 3322
(2009/12/01)
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- One-pot, three-step preparation of alkyl and aryl alkylcarbamates from S-methyl N-alkylthiocarbamates
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A general procedure for the synthesis of alkyl and aryl alkylcarbamates starting from the corresponding 5-methyl N-alkylthiocarbamates is described. This procedure consists of three steps that are carried out in a one-pot fashion, without isolating the intermediate N-alkylcarbamoyl chlorides or alkyl isocyanates. All the target products were obtained in high yields (16 examples, average yield 91%). To be noted is the recovery of a co-product of industrial interest, dimethyl disulfide, in a half mole amount for each mole of thiocarbamate, with complete exploitation of the reagent. The alkyl isocyanates, if required, can also be isolated in high yields. Georg Thieme Verlag Stuttgart.
- Artuso, Emma,Degani, Iacopo,Fochi, Rita,Magistris, Claudio
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experimental part
p. 1612 - 1618
(2009/04/03)
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- Synthesis and structure of N-alkyl(aryl)aminocarbonyl-1,4-benzoquinone imines
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New N-alkyl(aryl)aminocarbonyl-1,4-benzoquinone imines were synthesized by reaction of isocyanates with the corresponding substituted 4-aminophenols, and their structure was determined on the basis of 1H and 13C NMR spectra and X-ray diffraction data.
- Avdeenko,Konovalova,Sergeeva,Zubatyuk,Palamarchuk,Shishkin
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experimental part
p. 1765 - 1772
(2009/09/05)
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- METHOD FOR THE REDUCTION OF CHLORINE-CONTAINING COMPONENTS IN ORGANIC ISOCYANATES
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The invention relates to a method for largely eliminating chlorine compounds from organic isocyanates or isocyanate mixtures by contacting said isocyanates or isocyanate mixtures with a water-containing inert gas flow or an organic material having a cation-exchanging effect. The inventive method allows the isocyanates to be gently freed from chorine-containing compounds and is particularly suitable for temperature-sensitive isocyanates.
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Page/Page column 10
(2008/06/13)
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- Efficient synthesis of 2,9-disubstituted 8-hydroxyadenine derivatives
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An efficient and general method for the synthesis of 2,9-disubstituted 8-hydroxyadenines, which are expected to have various biological activities, was realized. 5-amino-4-cyano-2-hydroxyimidazoles(1) were prepared from aminomalononitrile and isocyanates as key intermediates. The condensation of 1a with amidines, imidates, guanidine, urea and thioureas afforded 8-hydroxyadenines (2-6) possessing various substituents at the 2-position. Furthermore, selective alkylation of 2-amino- and 2-hydroxyadenines (4 and 6) successively proceeded to give the corresponding 2-alkylamino- and 2-alkoxyadenines (5 and 7), respectively. 2-Alkythioadenines (15) were prepared by an analogous reaction of 1a with benzoyl isothiocyanate and subsequent S-alkylation. The imidazoles 1 are most useful intermediated for the synthesis of 8-hydroxyadenine derivatives.
- Hirota, Kosaku,Kazaoka, Kazunori,Niimoto, Itaru,Sajiki, Hironao
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p. 1354 - 1365
(2007/10/03)
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- Radical ring closures of 4-isocyanato carbon-centered radicals
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The 2-(2-isocyanatophenyl)ethyl radical was generated from the corresponding bromide with tributyltin and tris(trimethylsilyl)silyl radicals and shown to ring close in the 6-endo-mode to afford 3,4-dihydro-1H-quinolin-2-one as the major product. Cyclization in the 5-exo-mode to produce 2,3-dihydroindole-1-carbaldehyde, after hydrogen abstraction, was a minor reaction. Rate constants for the two processes were estimated and compared with reaction enthalpies computed by the DFT method.
- Minin, Patricia L.,Walton, John C.
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p. 2960 - 2963
(2007/10/03)
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- Sulfur containing dihydrophthalazine antagonists of excitatory amino acid receptors
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Substituted dihydrophthalazine sulfur containing compositions are provided which are active as non-NMDA ionotropic excitatory amino acid (EAA) receptor antagonists. The compositions are useful for treating disorders associated with excessive activation of the non-NMDA subtype of the ionotropic EAA receptor. The compounds further are useful as testing agents to identify and characterize other compounds for the treatment of these disorders. The compounds are useful therapeutically as sedatives or for the treatment of neurosychopharmacological disorders such as stroke, ischemia and epilepsy. The compositions may be provided in combination with a suitable carrier for oral or parenteral administration. The compounds may be administered orally or parenterally for the treatment of a variety of disorders associated with non-NMDA EEA receptor function.
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- Azulene derivatives
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The invention provides novel azulene derivatives of general formula I wherein R1 to R6 have the significance given in the description, as well as their tautomers, enantiomers, diastereomers, racemates and physiologically compatible salts or esters and substances which are hydrolyzed or metabolized in vivo to compounds of formula I. The invention is also concerned with a process and intermediates for the manufacture of the above compounds, pharmaceutical compositions which contain such compounds as well as the use of these compounds in the treatment of inflammatory conditions.
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- Synthesis and solid state and solution characterization of mono- and di-(η1-C) carbamoyl-palladium complexes. New efficient palladium-catalyzed routes to carbamoyl chlorides: Key intermediates to isocyanates, carbamic esters, and ureas
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The catalytic conversion of primary and secondary amines into isocyanates or carbamoyl chlorides is performed using palladium complexes. The palladium-based catalytic systems is very active and avoids the synthesis of phosgene. The palladium (II) complex
- Aresta, Michele,Giannoccaro, Potenzo,Tommasi, Immacolata,Dibenedetto, Angela,Lanfredi, Anna Maria Manotti,Ugozzoli, Franco
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p. 3879 - 3889
(2008/10/08)
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- 2-ureido-benzamide derivatives
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This invention is concerned with 2-ureido-benzamide compounds of the formula (1) STR1 in which R1 is H, halogen atom, (C1 -C4)alkyl, (C1 -C4)alkoxy or (C1 -C4)dialkylamino and R2 is H, halogen atom, hydroxy, nitro, (C1 -C4)alkyl, (C1 -C4)alkoxy, (C3 -C6) cycloalkylmethoxy, (C1 -C4) alkylthio, (C1 -C4) alkylsulfinyl, (C1 -C4)alkylsulfonyl or STR2 wherein j is an integer of from 0 to 2 and R3 and R4 are each independently H, (C1 -C4)alkyl, (C1 -C4)alkanoyl, (C1 -C4)alkylsulfonyl or (C1 -C4)alkylcarbamoyl, NR3 R4 can to form a pyrrolidine, piperidine, morpholine, imidazole or pyrazole ring; X is a (C3 -C15)alkyl, (C3 -C6) cycloalkyl, (C3 -C6) cycloalkylmethyl, ω-(C1 -C4) alkoxy-(C1 -C4) alkyl group or STR3 wherein k is an integer of from 1 to 4 and R5 and R6 are each independently H, Y is H or (C1 -C4)alkyl and Z is STR4 wherein m is an integer of from 0 to 4.
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- Development of chiral N-alkylcarbamates as new leads for potent and selective H3-receptor antagonists: Synthesis, capillary electrophoresis, and in vitro and oral in vivo activity
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Novel carbamates as derivatives of 3-(1H-imidazol-4-yl)propanol with an N-alkyl chain were prepared as histamine H3-receptor antagonists. Branching of the N-alkyl side chain with methyl groups led to chiral compounds which were synthesized stereospecifically by a Mitsunobu protocol adapted Gabriel synthesis. The optical purity of some of the chiral compounds was determined (ee > 95%) by capillary electrophoresis (CE). The investigated compounds showed pronounced to high antagonist activity (K(i) values of 4.1-316 nM) in a functional test for histamine H3 receptors on rat cerebral cortex synaptosomes. Similar H3-receptor antagonist activities were observed in a peripheral model on guinea pig ileum. No stereoselective discrimination for the H3 receptor for the chiral antagonists was found with the in vitro assays. All compounds were also screened for central H3-receptor antagonist activity in vivo in mice after po administration. Most compounds were potent agents of the H3-receptor-mediated enhancement of brain N(τ)- methylhistamine levels. The enantiomers of the N-2-heptylcarbamate showed a stereoselective differentiation in their pharmacological effect in vivo (ED50 of 0.39 mg/kg for the (S)-derivative vs 1.5 mg/kg for the (R)- derivative) most probably caused by differences in pharmacokinetic parameters. H1- and H2-receptor activities were determined for some of the novel carbamates, demonstrating that they have a highly selective action at the histamine H3 receptor.
- Sasse, Astrid,Kiec-Kononowicz, Katarzyna,Stark, Holger,Motyl, Malgorzata,Reidemeister, Sibylle,Ganellin, C. Robin,Ligneau, Xavier,Schwartz, Jean-Charles,Schunack, Walter
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p. 593 - 600
(2007/10/03)
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- Preparation of isocyanates from primary amines and carbon dioxide using Mitsunobu chemistry
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Primary alkylamines 1 and hindered arylamines 1 give high yields of isocyanates 5 when reacted with carbon dioxide and the Mitsunobu zwitterions 4 generated from dialkyl azodicarboxylates and Bu3P in dichloromethane at - 78°C. Use of Ph3P still gave high yields of isocyanates from reactions of primary alkylamines, but only low yields were obtained from reactions of aromatic amines. Reactions which failed to give high yields of isocyanates gave either carbamoylhydrazines 6 and/or dicarbamoylhydrazines 10 and/or triazolinones 7. The triazolinones were shown to arise from reactions of reactive aryl isocyanates with the Mitsunobu zwitterion. The carbamoylhydrazines were shown not to arise from reaction of isocyanate with reduced dialkyl azodicarboxylates, and a mechanism for their formation is proposed. Single-crystal X-ray analyses confirmed the structures of 6, 7, and 10.
- Saylik, Dilek,Horvath, Michael J.,Elmes, Patricia S.,Jackson, W. Roy,Lovel, Craig G.,Moody, Keith
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p. 3940 - 3946
(2007/10/03)
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- Synthesis of isocyanates from carbamate esters employing boron trichloride
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The conversion of carbamate esters to isocyanates and diisocyanates of industrial importance is possible using BCl3 in the presence of Et3N; the reaction is simple in execution and work-up, occurring under mild conditions and affording isocyanates in excellent yields.
- Butler,Alper
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p. 2575 - 2576
(2007/10/03)
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- Reactivity of Carbamoyl Radicals. A New, General, Convenient Free-Radical Synthesis of Isocyanates from Monoamides of Oxalic Acid
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A new, general, simple synthesis of isocyanates was developed by oxidation of monoamides of oxalix acid with peroxydisulfate catalyzed by Ag and Cu salts.The reaction was carried out in a two-phase system (water and an organic solvent), and it is suitable also for practical applications, due to the simple experimental conditions and the inexpensive as well as nontoxic reagents.The first example of homolytic intramolecular aromatic carbamoylation is also reported.
- Minisci, Francesco,Fontana, Francesca,Coppa, Fausta,Yan, Yong Ming
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p. 5430 - 5433
(2007/10/02)
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- Carbamoyl complexes as a source of isocyanates or carbamyl chlorides
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Isocyanates or carbamyl chlorides have been prepared by reaction of carbamoyl complexes of nickel and palladium with CuCl2.Isocyanates are selectively produced from the carbamoyl complexes of primary amines, , (L=2,6-bis(diphenylphosphinomethyl) pyridine; R=C6H5, p-CH3C6H4, or p-ClC6H4)) and , whereas carbamoyl complexes of secondary amines, such as , afford carbamyl chloride.As expected, the reaction of the resulting isocyanates or carbamyl chlorides in situ with alcohols or amines produces carbamates or N,N'-substituted ureas, respectively.Key words: Carbamyl chloride; Carbamate; Carboxamide; Chloroformamide; Complex; Isocyanates; Palladium; Phosphine; Synthesis
- Giannoccaro, Potenzo,Tommasi, Immacolata,Aresta, Michele
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- Reactivity of Carbamoyl Radicals: the First General and Convenient Free-radical Synthesis of Isocyanates
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The first free-radical synthesis of isocyanates was performed by oxidation of oxalic acid monoamides by S2O82-, catalysed by silver(I) and copper(II) salts, in a two-phase system.
- Minisci, Francesco,Coppa, Fausta,Fontana, Francesca
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p. 679 - 680
(2007/10/02)
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- Oxygen-containing titanocenes, and the use thereof
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Titanocenes of the formula I STR1 in which R1 are cyclopentadienyl? groups and R2 and R3 are aromatic radicals which are substituted in both ortho-positions by fluorine and, in addition, are substituted by an acyloxy group are suitable as photoinitiators for the photopolymerization of ethylenically unsaturated compounds.
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- Orally Active β-Lactam Inhibitors of Leukocyte Elastase-1. Activity of 3,3-Diethyl-2-azetidinones
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A thorough analysis of the mechanism of inhibition of human leukocyte elastase (HLE) by a monocyclic β-lactam and the mechanism of β-lactam hydrolysis led to the preparation of potent and highly stable inhibitors of HLE.This work led to the identification of 4--3,3-diethyl-1-carbonyl>-2-azetidinone (2) as the first orally active inhibitor of human leukocyte elastase (HLE).Analogs of 2 with different substituents on the urea N were synthesized and evaluated for their activity in vitro against HLE as well as in vivo in a hamster lung hemorrhage model.Compounds with a methyl or a methoxy group in the para position of the benzene ring were very potent in both assays.The results are discussed on the basis of the proposed model for the binding of this class of inhibitors to HLE and a possible mechanism of inhibition is presented.
- Shah, Shrenik K.,Dorn, Conrad P.,Finke, Paul E.,Hale, Jeffrey J.,Hagmann, William K.,et al.
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p. 3745 - 3754
(2007/10/02)
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- Oxidatively Assisted Alkylation of Sodium Nitrocyanamide and Sodium Azide
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m-Chloroperbenzoic acid (MCPBA) oxidatively assisted reactions at 25 deg C between straight chain primary alkyl iodides and sodium nitrocyanamide to give corresponding alkyl nitrocyanamides (N-alkylation) and N-alkoxy-N'-cyanodiazene N-oxides (O-alkylation).Each alkyl nitrocyanamide thermolysed to an alkyl isocyanate.In the absence of oxidative assistance sodium nitrocyanamide suspended in an inert solvent (25 deg C to 110 deg C) did not convert straight chain primary alkyl halides.Simple secondary and tertiary alkyl iodides and isobutyl iodide in the presence of MCPBA and sodium nitrocyanamide were converted to intractable mixtures that did not contain detectable amounts of alkyl nitrocyanamides, isocyanates, or N-alkoxy-N'-cyanodiazene N-oxides.This differential reactivity between the various types of alkyl iodides was supported by a similar conversion of straight chain primary alkyl iodides to corresponding azides and other alkyl iodides to intractable mixtures on treatment with sodium azide under conditions that brought about no reaction in the absence of oxidative assistance of MCPBA.Alkyl iodides were unreactive (25 deg C to 110 deg C) to sodium cyanate in the presence or absence of peroxides.
- Manimaran, Thanikavelu,Wolford, Lionel T.,Boyer, Joseph H.
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p. 2525 - 2532
(2007/10/02)
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- ISOCYANATES BLOQUES : ETUDE CINETIQUE ET THERMODYNAMIQUE
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A kinetic and thermodynamic study of the deblocking of urethanes is presented; the blocking agents are phenols, aliphatic alcohols and a polyether.The deblocking occurs via the elimination-addition mechanism.In the transamination reaction, the rate determining step is the amine catalyzed dissociation of the blocked isocyanate.The equilibrium constants of these reactions give the relative stability of blocked isocyanates.The dissociation equilibrium of several urethanes were also determined; temperature higher than 170 deg C are required to obtain a significant dissociation in the case of usual urethanes.
- Aguirre, I. de,Collot, J.
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- Process for producing an aliphatic isocyanate
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A process for producing an aliphatic isocyanate from an aliphatic primary amine comprising a carbonylation step in which an aliphatic primary amine is allowed to react with carbon monoxide at a temperature of about 100°-250° C. in the presence of an aromatic hydroxyl compound having a pKa value of not more than about 11, molecular oxygen and a catalyst system comprising at least one member selected from palladium and rhodium metals and components thereof and at least one member selected from iodine and bromine and compounds thereof and a combined separation and recovery step comprising a pyrolysis-distillation reaction in which the mixture of carbonylated products is heated to a temperature of from about 100° to 300° C.
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- MECHANISTIC FEATURES OF COBALOXIME(II) CATALYZED OXIDATIONS WITH DIOXYGEN
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Cobaloxime(II) derivatives of the formula Co(Hdmg)2Ln, where Hdmg- is the monoanion of dimethylglyoxime, L is Ph3P, py and Et3N and n = 1 or 2, are active catalysts of dehydrogenation and oxygen insertion reactions at room temperature and atmospheric O2 pressure.Hydrogen peroxide is not an intermediate and inactive cobaloxime(III) derivatives are not formed during the reactions.ESR, UV-Vis and polarography data point to successive O-atom transfer from superoxocobaloxime(III) and μ-peroxodicobaloxime(III) to the substrates via a cobaltyl ion type oxenoid reagent.
- Nemeth, S.,Fuelep-Poszmik, A.,Simandi, L. I.
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p. 461 - 470
(2007/10/02)
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- Process for the preparation of organic mono- and polyisocyanates
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A process for the preparation of organic mono- and polyisocyanates is described, in which a hydrogen chloride adduct of a trisubstituted urea is thermally decomposed to form the isocyanate. The hydrogen chloride adduct at minimum contains the stoichiometric amount of HCl, and at maximum a 10 mole-% excess. The process is carried out in a closed system at a temperature between about 80° and 180° C.; the reaction is effected either in a melt or in the presence of an inert organic solvent.
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- Manufacture of aliphatic or cycloaliphatic isocyanates
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Aliphatic and cycloaliphatic isocyanates are manufactured by thermal decomposition of aliphatic or cycloaliphatic carbamic acid chlorides in the presence of an inert organic solvent of lower boiling point than that of the isocyanate formed. The decomposition is carried out in a reaction vessel surmounted by a rectifying unit, which in turn is surmounted by a reflux condenser, the isocyanate formed being condensed in the rectifying unit at a temperature above the boiling point of the solvent.
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- Preparation of organic isocyanates
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A process for the manufacture of organic isocyanates which comprises reacting a substituted urea having at least one unsubstituted NH2 group with nitrous acid in the presence of a water-immiscible solvent and a phase transfer agent.
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- Process for preparing alkyl isocyanates
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Alkylisocyanates are prepared by reacting a phenol or substituted phenol and phosgene in a halogenated hydrocarbon solvent with aqueous alkali metal hydroxide to produce a corresponding chloroformate, reacting the resulting chloroformate solution with aqueous alkylamine to give a corresponding N-alkylcarbamate which, after solvent is stripped, is then pyrolyzed to yield the alkyl isocyanate. Solvent and the starting phenol may be recovered and recycled to the process.
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- Optical brightening agents of naphthalimide derivatives
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A naphthalimide derivative having the formula STR1 wherein R is an alkyl, or cycloalkyl, an aralkyl, a haloalkyl, an alkoxyalkyl, a hydroxyalkyl, an N,N-dialkylaminoalkyl, an unsubstituted or halogen-, alkyl-, alkoxy- or hydroxy-substituted aryl, or an ammoniumalkyl; X is a group of the formula, STR2 wherein A is STR3 or an unsubstituted or halogen-substituted arylene, or a group of the formula, STR4 wherein R1 is hydrogen, an alkyl, phenyl, a hydroxyalkyl, or an alkoxyalkyl; Y is --CO--, --COO--, --CONR3 -- (where R3 is hydrogen or an alkyl), or --SO2 --; R2 is hydrogen, an alkyl, a cycloalkyl, an aralkyl, a haloalkyl, an alkyl- or aryl-substituted amino-alkyl, an unsubstituted or halogen-, alkyl-, alkoxy-, hydroxy-, amino- or alkylamino-substituted aryl, a group of the formula, STR5 (where R, R1 and Y are as defined above and R4 is a bivalent group), or a group of the formula, (where R5 is direct linkage or a bivalent group; Q+ is a substituted ammonium, a cycloammonium or a hydrazinium; and α- is an anion), Which is useful for optically brightening an organic polymer material.
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- Production of isocyanates from substituted ureas
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A method for the production of isocyanic acid esters (isocyanates) from substituted ureas by thermally decomposing the substituted urea at elevated temperatures while said urea is dissolved in a suitable inert solvent and in the presence of an inert carrier agent to produce the isocyanate and/or amine as overhead products in the vapor phase minimizing the recombination of the isocyanate and the amine and separately recovering the isocyanate and amine.
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