- Direct conversion of carboxylic acids to various nitrogen-containing compounds in the one-pot exploiting curtius rearrangement
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Herein we report, a single-pot multistep conversion of inactivated carboxylic acids to various N-containing compounds using a common synthetic methodology. The developed methodology rendered the use of carboxylic acids as a direct surrogate of primary amines, for the synthesis of primary ureas, secondary/tertiary ureas, O/S-carbamates, benzoyl ureas, amides, and N-formyls, exploiting the Curtius reaction. This approach has a potential to provide a diversified library of N-containing compounds, starting from a single carboxylic acid, based on the selection of the nucleophile.
- Kumar, Arun,Kumar, Naveen,Sharma, Ritika,Bhargava, Gaurav,Mahajan, Dinesh
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p. 11323 - 11334
(2019/09/10)
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- A practically simple, catalyst free and scalable synthesis of: N -substituted ureas in water
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A practically simple, mild and efficient method is developed for the synthesis of N-substituted ureas by nucleophilic addition of amines to potassium isocyanate in water without organic co-solvent. Using this methodology, a variety of N-substituted ureas (mono-, di- and cyclic-) were synthesized in good to excellent yields with high chemical purity by applying simple filtration or routine extraction procedures avoiding silica gel purification. The developed methodology was also found to be suitable for gram scale synthesis of molecules having commercial application in large volumes. The identified reaction conditions were found to promote a unique substrate selectivity from a mixture of two amines.
- Tiwari, Lata,Kumar, Varun,Kumar, Bhuvesh,Mahajan, Dinesh
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p. 21585 - 21595
(2018/06/26)
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- Design and biological evaluation of novel 4-(2-fluorophenoxy)quinoline derivatives bearing an imidazolone moiety as c-Met kinase inhibitors
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A series of 4-(2-fluorophenoxy)quinoline derivatives containing an imidazolone moiety were designed, synthesized and evaluated for their in vitro biological activities against c-Met kinase and four cancer cell lines (A549, H460, HT-29 and MKN-45). Most compounds showed moderate to excellent activities in enzyme and cellular assays. The most promising analog, 58 (c-Met IC50 = 1.42 nM), displayed 2.1-, 8.6-fold increase against H460, and MKN-45 cell lines, respectively, compared with foretinib. An analysis of structure-activity relationships revealed that an ortho substituted phenyl ring as well as an N-unsubstituted imidazolone linker is favorable for antitumor activity.
- Liao, Weike,Hu, Gang,Guo, Zhuang,Sun, Deyu,Zhang, Lixia,Bu, Yanxin,Li, Yingxiu,Liu, Yajing,Gong, Ping
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p. 4410 - 4422
(2015/08/03)
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- CRYSTALLINE ACID ADDITION SALTS AND THEIR USE AS ENZYME INHIBITORS
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A crystalline acid addition salt of the compound of formula (I), said salt being selected from the hydrogen sulfate, p-toluene sulfonate, naphthalene-2-sulfonate, fumarate, and ethanesulfonate salts thereof. The said salts are inhibitors of human neutrophil elastase (HNE), and thus of use in the treatment of inflammatory conditions, including those of the respiratory tract, especially when administered by inhalation for pulmonary delivey.
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Page/Page column 14
(2010/04/27)
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- THE CLAIMED INVENTION RELATES TO NOVEL 4-PIPERIDINECARBOXAMIDE AND THE USE THEREOF FOR THE PREPARATION OF MEDICAMENTS AGAINST 5-HT2A RECEPTOR-RELATED DISORDERS
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The present invention relates to compounds of Formula (I) wherein R and R′ are as described herein, processes for preparing the compounds, pharmaceutical compositions comprising the compounds, and use of the compounds and compositions in the prophylaxis or treatment of a 5-HT2A receptor-related disorder.
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Page/Page column 14
(2008/06/13)
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- Phenylureas. Part 1. Mechanism of the basic hydrolysis of phenylureas
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The mechanism of the hydrolytic decomposition of phenylureas in basic media in the pH range 12 to 14 is investigated. In this pH range a levelling of the rate-pH curve is observed as well as a change of the substituent influence on the hydrolysis rate. These experimental findings suggest the formation of an unreactive side product of the phenylurea in a parasitic side equilibrium at sufficiently high pH. The urea dissociates at the aryl-NH group to give its conjugate base. For the hydrolytic decomposition of phenylureas an addition-elimination mechanism is proposed as has been established for the alkaline hydrolysis of carboxylic acid esters and amides.
- Laudien,Mitzner
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p. 2226 - 2229
(2007/10/03)
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- USE OF ISOCYANIC ACID FOR THE PREPARATION OF SUBSTITUTED UREAS
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A thermogravimetric study was carried out on the thermolysis of cyanuric acid and conditions were found for carrying out this reaction to give gaseous isocyanic acid.Dosing this acid in the vapor of inert organic solvents gave systems used for the selective synthesis of monosubstituted ureas.The reaction of gaseous isocyanic acid with amine vapor selectively gave highly pure N-cyclohexylurea and N,N'-bis(3-trifluoromethylphenyl)urea.
- Kirpichev, V. P.,Karachinskii, S. V.,Dragalov, V. V.,Peshkova, O. Yu.
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p. 1651 - 1653
(2007/10/02)
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