- Iron-promoted one-pot approach: Synthesis of isothiocyanates
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We have established a facile and versatile synthesis for the construction of isothiocyanates from their respective amines in the presence of an eco-friendly, inexpensive, easily available Iron catalyst under mild conditions. This reaction provides the target products through the formation of thiocarbamate salt as an intermediate. Both aromatic amines and aliphatic amines provided the respective target products in moderate to high yield under optimized reaction conditions. However, electron withdrawing substituents were difficult to give target product at room temperature, whereas, they obtained final products in good yield at moderate temperature. In addition, mechanistic studies were revealed that the synthetic route involved iron based subsequent reactions of addition and removal of sulfur.
- Pendem, Venkata Bhavanarushi,Nannapaneni, Madhavi
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p. 485 - 490
(2020/02/18)
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- Synthesis and antitumor activity of novel pyridazinone derivatives containing 1,3,4-thiadiazole moiety
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A series of novel pyridazinone derivatives containing the 1,3,4-thiadiazole moiety were synthesized and characterized by 1H NMR, 13C NMR, spectroscopies HRMS and IR. Among them, the structure of compound 5c (2-(Tert-butyl)?4-chloro-5-((5-((2-ethylphenyl)amino)?1,3,4-thiadiazol-2-yl)thio)pyridazin-3(2H)-One) was unambiguously confirmed via single crystal X-ray diffraction analysis. The inhibitory activity of all the target compounds against MGC-803 and Bcap-37 was determined by MTT assay, with doxorubicin (the inhibition rates were 95.5 ± 0.4% and 95.7 ± 1.0% respectively) as a control. The preliminary results showed that the inhibitory activity of compound 5n (2-(Tert-butyl)?4-chloro-5-((5-((3-fluorophenyl)amino)?1,3,4-thiadiazol-2-yl)thio)pyridazin-3(2H)-One) was superior to the others. The inhibition rates of MGC-803 and Bcap-37 cells were 86.3 ± 2.2% and 92.3 ± 0.6% at a concentration of 10 μmol/L, respectively. The preliminary structure-activity relationship showed that when the 2-position of the benzene ring was substituted by a methyl group, such as compound 5j (2-(Tert-butyl)?4-chloro-5-((5-((2,3-dimethylphenyl)amino)?1,3,4-thiadiazol-2-yl)thio)pyridazin-3(2H)-One), it exhibited good anticancer activity on MGC-803 cells. Besides, introducing fluorine, chlorine, or trifluoromethyl group onto the benzene ring, such as compound 5 m (2-(Tert-butyl)?4-chloro-5-((5-((4-(trifluoromethoxy)phenyl)amino)?1,3,4-thiadiazol-2-yl)thio)pyridazin-3(2H)-One), displayed good anticancer activity on MGC-803 and Bcap-37 cells.
- Qin, Junhu,Zhu, Mei,Zhu, Hongmei,Zhang, Liqiong,Fu, Yihong,Liu, Jiamin,Wang, Zhenchao,OuYang, Guiping
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p. 592 - 599
(2020/03/16)
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- Design, computational studies, synthesis and biological evaluation of thiazole-based molecules as anticancer agents
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Background: Abolition of cancer warrants effective treatment modalities directed towards specific pathways dysregulated in tumor proliferation and survival. The antiapoptotic Bcl-2 proteins are significantly altered in several tumor types which position them as striking targets for therapeutic intervention. Here we designed, computationally evaluated, synthesized, and biologically tested structurally optimized thiazole-based small molecules as anticancer agents. Methods: The virtually designed 200 molecules were subjected to rigorous docking and in silico ADME-Toxicity studies. Out of this, 23 skeletally diverse thiazole-based molecules which passed pan assay interference compounds (PAINS) filter and were synthetically feasible were synthesized in 3 steps using cheap and readily available reagents. The molecules were in vitro evaluated against Bcl-2-Jurkat, A-431 cancerous cell lines and ARPE-19 cell lines. Molecular Dynamics (MD) simulation studies were performed to analyse conformational changes induced by ligand 32 in Bcl-2. Flow cytometry analysis of compound 32 treated Bcl-2 cells was done to check apoptosis. Results: The molecules exhibited appreciable interactions with Bcl-2 and were having acceptable drug like properties as tested in silico. The multi step synthesis yielded 23 skeletally diverse thiazole-based molecules in up to 80% yield. The molecules simultaneously inhibited Bcl-2 Jurkat cells in vitro without causing detectable toxicity to normal cells (ARPE-19 cells). Among them molecules 32, 50, 53, 57 and 59 showed considerable activities against Bcl-2 Jurkat and A-431cell lines at concentrations ranging from 32–46 μM and 34–52 μM, respectively. The standard doxorubicin exhibited IC50 in Bcl-2 Jurkat and A-431cell lines at 45.87 μM and 42.37 μM, respectively. The molecule 32, almost equipotent in both the cell lines was subjected to molecular dynamics (MD) simulation with Bcl-2 protein (4IEH). It was shown that 32 interacted with protein majorly via hydrophobic interactions and few H-bonding interactions. Fluorescence-activated cell sorting (FACS) analysis established that molecule is dragging cancerous cells towards apoptosis. Discussion and conclusion: The chemical intuition was checked by computation coupled with biological results confirmed that thiazole-based hits have the potential to be developed downstream into potent and safer leads against antiapoptotic Bcl-2 cells.
- Anuradha,Patel, Sagarkumar,Patle, Rajkumar,Parameswaran, Preethi,Jain, Alok,Shard, Amit
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- Na2S2O8-mediated efficient synthesis of isothiocyanates from primary amines in water
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We have developed two green, practical, and efficient procedures, including a one-pot one, to synthesize isothiocyanates from amines and carbon disulfide via desulfurization with sodium persulfate. Water is used as the solvent. Basic conditions are necessary for good chemoselectivity for isothiocyanates. Structurally diverse linear and branched alkyl amines and aryl amines are readily converted to isothiocyanates by the two procedures in satisfactory yields. Halogens, benzylic C-H bonds, methylthio, nitro, ester, alkenyl, electron-rich or -deficient (hetero)aryls, acetylenyl, and even phenolic and alcoholic hydroxyls are well tolerated. The one-pot procedure in water can also be used to realize the preparation of chiral isothiocyanates from chiral amines, and the modification of bioactive structures with free amino groups. In large-scale preparation, simple and practical purification procedures independent of column chromatography are developed.
- Fu, Zhicheng,Yuan, Wenhao,Chen, Ning,Yang, Zhanhui,Xu, Jiaxi
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supporting information
p. 4484 - 4491
(2018/10/17)
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- One-pot three-component tandem reaction: Synthesis of aryl/alkyl cyanamides libraries and their further conversion into tetrazole derivatives
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We have developed methodology for the synthesis of aryl/alkyl cyanamides from amines in one-pot four steps reaction using cheap, readily available and air stable copper source as catalyst under mild reaction conditions. We have also studied the application of cyanamides. In this connection, we could construct aryl tetrazolamine from cyanamides using click reaction.
- Mandapati, Usharani,Mandapati, Pavan,Pinapati, Srinivasarao,Tamminana, Ramana,Rudraraju, Rameshraju
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supporting information
p. 500 - 510
(2018/02/06)
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- Copper promoted desulfurization towards the synthesis of isothiocyanates
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The cheap, readily available and air stable catalyst was used as the desulfurization agent for the conversion of aniline to isothiocyanates in one pot two step reaction under mild reaction conditions.
- Mandapati, UshaRani,Pinapati, Srinivasarao,Rudraraju, RameshRaju
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p. 125 - 128
(2016/12/26)
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- A novel one-pot synthesis of isothiocyanates and cyanamides from dithiocarbamate salts using environmentally benign reagent tetrapropylammonium tribromide
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A highly efficient and simple protocol for the synthesis of isothiocyanates and cyanamides from their respective amines in the presence of a mild, efficient, and non-toxic reagent tetrapropylammonium tribromide is described. High environmental acceptability of the reagents, cost effectiveness and high yields are the important attributes of this methodology.
- Kuotsu, Neivotsonuo Bernadette,Jamir, Latonglila,Phucho, Tovishe,Sinha, Upasana Bora
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p. 832 - 841
(2018/01/17)
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- Synthesis of 4-phenylthieno[2, 3-e][1, 2, 4]triazolo[4, 3-a]pyrimidine-5 (4H)-one derivatives and evaluation of their anti-inflammatory activity
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A series of 4-phenylthieno[2, 3-e][1, 2, 4]triazolo[4, 3-a]pyrimidine-5 (4H)-ones (5a-p) with triazole or other heterocyclic substituents (6-11) was synthesized and the compounds were evaluated for their anti-inflammatory activity using the xylene-induced ear-edema test. Pharmacological analyses showed that the compound 4- (4-chlorophenyl)thieno[2, 3-e][1, 2, 4]triazolo[4, 3-a]pyrimidine- 5 (4H)-one (5m) exhibited the greatest anti-inflammatory activity (50.48% inhibition, 30 min after intraperitoneal administration) and was more potent than the reference drug, indomethacin. The peak activity of 5m was observed 4 h after oral administration, and it showed a higher anti-inflammatory activity than indomethacin did at a dose of 100 mg/kg.
- Pan, Fu-Jun,Wang, Shi-Ben,Liu, Da-Chuan,Gong, Guo-Hua,Quan, Zhe-Shan
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p. 141 - 148
(2016/03/12)
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- An efficient methodology for the synthesis of thioureas from amine mediated by a cobalt source
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The cheap, readily available and air stable cobalt catalyst was used as the desulfurization agent for the conversion of aniline to thioureas in one pot three step reaction under mild reaction conditions. The reactions are rapid and facile and accomplished at room temperature.
- Seelam, Mohan,Shaikh, Baji Vali,Tamminana, Ramana,Kammela, Prasada Rao
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supporting information
p. 5297 - 5300
(2016/11/11)
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- Cobalt mediated by desulfurization toward the synthesis of isothiocyanates
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A highly efficient and simple protocol for the construction of aromatic and aliphatic isothiocyanates from their respective amines in the presence of cheap, readily available, and air-stable cobalt catalyst is described. All reactions were carried out under optimized reaction conditions and gave target products in good to excellent yields within shorter reaction time.
- Seelam, Mohan,Shaik, Bajivali,Kammela, Prasada Rao
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supporting information
p. 1759 - 1765
(2016/10/31)
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- Synthesis, acetylcholinesterase and alkaline phosphatase inhibition of some new 1,2,4-triazole and 1,3,4-thiadiazole derivatives
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A new series of 4,5-disubstituted-2,4-dihydro-3H-1,2,4-triazole-3-thiones (6as) and 2,5-disubstituted-1,3,4-thiadiazoles (7ah) was synthesized by intramolecular dehydrocyclization of various 1,4-disubstituted thiosemicarbazide derivatives (5as) by refluxing in 4N aqueous sodium hydroxide and by overnight stirring with polyphosphoric acid, respectively. The structures of these compounds were characterized by IR, 1H and 13C NMR, elemental analysis and mass spectroscopic studies. All the synthesized compounds were screened for their acetylcholinesterase and alkaline phosphatase inhibition studies. Most of the tested compounds showed promising activities, amongst them (6k) and (6q) showed excellent acetylcholinesterase inhibitory activity with IC50 0.2410.012 and 0.2600.013M, respectively, as compared with those of standard drug whereas the compound (6p), with IC50 0.0440.001M, was found to be the most potent inhibitor of alkaline phosphatase.
- Khan, Imtiaz,Hanif, Muhammad,Rama, Nasim Hasan,Hussain, Muhammad Tahir,Khan, Aftab Ahmed,Aslam, Muhammad Adil S.,Iqbal, Jamshed
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p. 1413 - 1419,7
(2020/09/02)
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- Environmentally benign one-pot synthesis of cyanamides from dithiocarbamates using I2 and H2O2
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An environmentally benign reaction is devised for the synthesis of cyanamides from dithiocarbamate salts using iodine and H2O 2. Taylor & Francis Group, LLC.
- Jamir, Latonglila,Sinha, Upasana Bora,Nath, Jayashree,Patel, Bhisma K.
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experimental part
p. 951 - 958
(2012/02/01)
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- Synthesis and reactivity studies of a new reagent, ethyltriphenylphosphonium tribromide
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A new reagent, ethyltriphenyl phosphonium tribromide (ETPPTB), has been synthesized and studied. Results show that the reagent is quite efficient for various reactions such as organic bominations, acylations, and isothiocyanate preparation. Copyright
- Jamir, Latonglila,Alimenla,Kumar, Anil,Sinha, Dipak,Sinha, Upasana B.
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p. 147 - 155
(2011/03/17)
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- Synthesis and biological evaluation of dihydroisoquinoline-2(1H)- carbothioamide derivatives as TRPV1 antagonists
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TRPV1 receptor is an important analgesia target. Its antagonists are expected to prevent pain perception by blocking the receptor directly. In this letter, eight dihydroisoquinoline-2(1H)-carbothioamide derivatives were designed and synthesized as TRPV1 antagonists. The benzene ring was modified with different substitutional groups. Preliminary biological tests suggested that the new compounds exhibited TRPV1 antagonist activity and different analgesia effects, some of which were promising as analgesia drugs.
- Qian, Hai,Chen, Wei,Zhang, Xiaoyan,Zhang, Huibin,Zhou, Jinpei,Huang, Wenlong,Jin,Dai, Dongyan
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p. 235 - 237
(2011/03/18)
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- Synthesis, antioxidant activities and urease inhibition of some new 1,2,4-triazole and 1,3,4-thiadiazole derivatives
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New series of 4,5-disubstituted-2,4-dihydro-3H-1,2,4-triazole-3-thiones (8a-j) and 2,5-disubstituted-1,3,4-thiadiazoles (9a-h) were synthesized by dehydrative cyclization of hydrazinecarbothioamide derivatives (7a-k) by refluxing in 4 N aqueous sodium hydroxide and by overnight stirring with polyphosphoric acid, respectively. The structures of the newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, elemental analysis and mass spectroscopic studies and the synthesized compounds were screened for their antioxidant and urease inhibition activities. N-(2,4-Dimethylphenyl)-5-(4-nitrophenyl)-1,3,4-thiadiazol-2-amine (9h) showed excellent antioxidant activity more than the standard drug whereas 4-(2,4-dimethylphenyl)-5-(3-nitrophenyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (8d) and 4-(2,3-dimethylphenyl)-5-phenyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (8e) exhibited potent urease inhibitory activities.
- Khan, Imtiaz,Ali, Sajid,Hameed, Shahid,Rama, Nasim Hasan,Hussain, Muhammad Tahir,Wadood, Abdul,Uddin, Reaz,Ul-Haq, Zaheer,Khan, Ajmal,Ali, Sajjad,Choudhary, M. Iqbal
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scheme or table
p. 5200 - 5207
(2011/01/04)
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- The thiocarbonyl 'S' is softer than thiolate 'S': A catalyst-free one-pot synthesis of isothiocyanates in water
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Treatment of the preformed or the in situ generated aryl/alkyl dithiocarbamates triethylammonium salt (ArNHCSS-.Et 3NH+) with methyl acrylate in an aqueous medium gave solely arylisothiocyanate (ArNCS), whereas the in situ generated aryl dithiocarbamic acid (ArNHCSS-.H+) yielded exclusively the thia-Michael adduct (ArNHCSSCH2CH2COOMe). This differential reactivity can be explained by two alternative mechanisms which is dependent both on the nature of the counter cation and on the pH of the reaction medium. Irrespective of the counter cations, the thiocarbonyl sulfur (=S) atom, having large orbital-coefficient, is softer compared to the thiol/thiolate sulfur (-SH/S-) in a dithiocarbamate salt and the former adds to the Michael acceptor by a 1,4-addition.
- Jamir, Latonglila,Ali, Abdur Rezzak,Ghosh, Harisadhan,Chipem, Francis A. S.,Patel, Bhisma K.
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experimental part
p. 1674 - 1678
(2010/07/04)
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- Molecular iodine mediated preparation of isothiocyanates from dithiocarbamic acid salts
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We have developed a general economical and environmentally benign method for the preparation of isothiocyanates from the corresponding dilhiocarbamic acid salts by using cheap and readily available reagent molecular iodine. This is perhaps the most efficient method reported so far for the synthesis of isothiocyanates. The reagent is easily available and nontoxic, and the precipitated sulfur can be removed easily; hence, this method is most suitable for large-scale synthesis. Wiley-VCH Verlag GmbH & Co. KGaA.
- Nath, Jayashree,Ghosh, Harisadhan,Yella, Mamesh,Patel, Bhisma K.
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experimental part
p. 1849 - 1851
(2009/08/07)
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- A one-pot preparation of cyanamide from dithiocarbamate using molecular iodine
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An efficient one-pot method for the synthesis of cyanamides from dithiocarbamate salts via a double desulfurization strategy using molecular iodine is disclosed. Dithiocarbamates, by the action of iodine yield isothiocyanates in situ, which on treatment with aqueous NH3 give thioureas. The thioureas so generated undergo further oxidative desulfurization with I2 giving corresponding cyanamides in good yields. Environmental benignity, cost effectiveness and high yields are the important attributes of this one pot procedure. The Royal Society of Chemistry 2009.
- Nath, Jayashree,Patel, Bhisma K.,Jamir, Latonglila,Sinha, Upasana Bora,Satyanarayana
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experimental part
p. 1503 - 1506
(2010/05/18)
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- Desulfurization mediated by hypervalent iodine(III): A novel strategy for the construction of heterocycles
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The desulfurization ability of diacetoxyiodobenzene (DIB) has been explored in the preparation of isothiocyanates from the corresponding dithiocarbamate salts. The in situ generated isothiocyanates reacted with o-phenylenediamine and o-aminophenol to form monothioureas, which, on treatment with a further equivalent of DIB in one pot, gave benzimidazoles and aminobenzoxazoles, respectively. Aliphatic 1,2-diamines on reaction with 2 equiv. of isothiocyanate followed by treatment with DIB gave imidazolidenecarbothioamides, whereas the treatment of aromatic 1,2-diaminebis(thioureas) yielded benzimidazoles with the concurrent formation of isothiocyanate. The driving force for the formation of the latter is the aromatization of the product. The use of DIB makes these methods simpler and more efficient, giving high yields of the desired products in one pot. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Ghosh, Harisadhan,Yella, Ramesh,Nath, Jayashree,Patel, Bhisma K.
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scheme or table
p. 6189 - 6196
(2009/05/27)
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- A simple construction of 2-phenylimino-1,3-thiazolidin-4-ones
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A new methodology for the construction of 2-phenylimino-1,3-thiazolidin-4-one skeleton is described. Reaction of maleic anhydride (5a) or maleimides (5b, 5c) with thiourea (6) gave the corresponding 2-imino-1,3-thiazolidin-4-ones (7) and (9) respectively. The reaction proceeded with high yield in polar solvents. In non-polar solvents at high temperature, however, isothiocyanate (8) was formed as a by-product presumably by the pyrolysis of thiourea (6). The proposed mechanism of the reaction was discussed.
- Hahn, Hoh-Gyu,Nam, Kee Dal,Mah, Heduck
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p. 1283 - 1289
(2007/10/03)
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- Phenyl -thiourea, -carbothioamide and -carbonothioamide derivatives
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Disclosed are various phenyl -thiourea, -carbothioamide and -carbonothioamide derivatives which are useful in alleviating symptoms and conditions of inflammation.
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