- Synthesis and SAR studies of potent H+/K+-ATPase and anti-inflammatory activities of symmetrical and unsymmetrical urea analogues
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A sequence of symmetrical and unsymmetrical urea derivatives 1–24 were synthesized and characterized by standard spectroscopic techniques. The synthesized analogues were tested for their in vitro H+/K+-ATPase and anti-inflammatory activities. The majority of the compounds showed outstanding activity, compared to that of omeprazole and indomethacin, usual standard drugs of antiulcer and anti-inflammatory, respectively. In particular, hydroxy, methyl, and methoxy derivatives 13–24 were the most active compounds possessing a significant amplify for diverse substituents on the benzene ring thus, contributing positively to gastric ulcer inhibition. Compounds 1–3 and 22–24 showed excellent anti-inflammatory activity due to the presence of electron-withdrawing groups (Cl and F) on the molecule.
- Rakesh, Kadalipura P.,Darshini, Nanjudappa,Vidhya, Sunnadadoddi L.,Rajesha,Mallesha, Ningegowda
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p. 1675 - 1681
(2017/06/27)
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- An unexpected reaction to methodology: An unprecedented approach to transamidation
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This report describes an unprecedented protocol for the synthesis of N,N′-substituted ureas using a cross-coupling method. Mono substituted ureas were modified by an economically viable and simple method using commercially available isocyanates and sodium hydride as the reagents. In addition, the method involves no expensive metal complexes or catalysts and all reactions are carried out at room temperature. Furthermore, both symmetrical and asymmetrical ureas were successfully obtained in single step reactions with reasonable yields.
- Rakesh,Ramesha,Shantharam,Mantelingu,Mallesha
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p. 108315 - 108318
(2016/11/30)
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- 1,2,3- and 1,2,4-triazolium salts, pyrazoles, and quinoxalines from diarylnitrilimines and isocyanides: A study of the scope
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Formation of the four title compounds has been found to be strongly dependent on substituents: 1,2,3-Triazolium salts 6 do not arise from nitrilimines 2 that have an electron- acceptor attached to either the C- or the N-phenyl group. Likewise tert-butyl and aryl isocyanides do not afford this class of compounds; from the former isocyanide, dequaternization products 7 are obtained instead, whereas from the latter 1,2,4-triazolium salts 11 are formed. Compounds 11 with a tert-butyl group at the ring are unstable too, giving rise to triazoles 13. Pyrazole formation (analogues of 14) is completely suppressed when both tert-butyl and aryl isocyanides are used, whereas access to this ring system works best with sec-alkyl isocyanides (the influence of substituents of 2 being almost negligible in this case). Formation of quinoxalines 23 which arise from intermediary 1,2-diazets 22 by ring expansion is much favoured on employment of 2 that bears a donator substituent at the N-phenyl group, and under this premise ring closure to 22 is virtually independent on the nature of the isocyanide. Formation of 23 is not observed with 2 having acceptor groups.
- Moderhack, Dietrich,Daoud, Ali
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p. 625 - 637
(2007/10/03)
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- PREPARATION AND PROPERTIES OF 3-ALKYL-i-ARYLNITROSOUREAS AND RELATED COMPOUNDS
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Nitrosation of 3-alkyl-1-arylureas was investigated with sodium nitrite in 99percent formic acid or with isoamyl nitrite in chloroform.The preparation of 3-alkyl-1-aryl-1-nitrosoureas was effectively performed by using isoamyl nitrite in the absence of acids, since the 1-nitrosoureas were isomerized to the 3-nitroso isomers by acids.The carbon-13 nuclear magnetic resonance and infrared spectral properties of the products were examined and their structural features are discussed.It was found that 3-alkyl-1-aryl-1-nitrosoureas decomposed to form alkyl isocyanates and 3-alkyl-1-(2-nitroaryl)ureas in carbon tetrachloride. 1,3-Rearrangement and transnitrosation also took place in this solvent.Keywords - 3-alkyl-1-arylnitrosourea; 3,3-diethyl-1-tolyl-1-nitrosourea; N-nitrosourea; nitrosation; 1,3-rearrangement; isomerization; transnitrosation; nitration
- Tanno, Masayuki,Sueyoshi, Shoko
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p. 1360 - 1371
(2007/10/02)
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