- Potent gonadotropin releasing hormone antagonists with low histamine- releasing activity
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The incorporation of Arg residues into position 6 of gonadotropin releasing hormone antagonists had resulted in compounds with increased in vivo potency but also made these analogues potent mast cell degranulators. We have focused on the substitution of position 8 by hArg(R)2 (N(G)-N(G)'- dialkylhomoarginine) substitutions, based on the hypotheses that the Arg-Pro sequence is of major importance for this side effect and that shielding of the charge may be an effective way to block degranulation. Analogues in four series were evaluated: (A) [N-Ac-D-Nal(2)1,D-pCl-Phe2,D-Pal- (3)3,6,Arg5,hArg(R)28,D-Ala10]GnRH, (B) [N-Ac-D-Nal(2)1,D-pCl- Phe2,D-Pal(3)3,6,hArg(R)25,8,D-Ala10]-GnRH, (C) [N-Ac-D-Nal(2)1,D- pCl-Phe2,D-Pal(3)3,6,hArg(R)28,D-Ala10]GnRH, (D) [N-Ac-D-Nal(2)1,D- pCl-Phe2,D-Pal(3)3,D-hArg(R)26,hArg(R)28,D-Ala10]GnRH. Although substitution by hArg(Et)2, hArg(Bu), hArg(CH2)3, and hArg(CH2CF3)2 was tested, in each series the hArg(Et)2 residue was superior. Two compounds were considered for clinical evaluation: [N-Ac-D-Nal(2)1,D-pCl-Phe2,D- Pal(3)3,6,hArg(Et)28,D-Ala10]GnRH and [N-Ac-D-Nal(2)1,D-pCl-Phe2,D- Pal(3)3,D-hArg(Et)26,hARg-(Et)28,D-Ala10]GnRH (ganirelix acetate). These compounds had high potency for ovulation suppression and low histamine- releasing potency in vitro (ED50 = 0.6, 0.29 μg/rat and EC50 = 196, 13 μg/mL, respectively). Ganirelix is currently in Phase II clinical trials and appears to be the most potent GnRH antagonist tested in humans (based upon ED50 for 24-h suppression of testosterone levels).
- Nestor Jr.,Tahilramani,Ho,Goodpasture,Vickery,Ferrandon
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Read Online
- Green and efficient synthesis of thioureas, ureas, primary: O -thiocarbamates, and carbamates in deep eutectic solvent/catalyst systems using thiourea and urea
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An efficient and general catalysis process was developed for the direct preparation of various primary O-thiocarbamates/carbamates as well as monosubstituted thioureas/ureas by using thiourea/urea as biocompatible thiocarbonyl (carbonyl) sources. This procedure used choline chloride/tin(ii) chloride [ChCl][SnCl2]2 with a dual role as a green catalyst and reaction medium to afford the desired products in moderate to excellent yields. Moreover, the DES can be easily recovered and reused for seven cycles with no significant loss in its activity. Besides, the method shows very good performance for synthesizing the desired products on a large scale.
- Bagherzadeh, Nastaran,Sardarian, Ali Reza,Inaloo, Iman Dindarloo
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supporting information
p. 11852 - 11858
(2021/07/12)
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- Cobalt-promoted one-pot reaction of isothiocyanates toward the synthesis of aryl/alkylcyanamides and substituted tetrazoles
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[Figure not available: see fulltext.] The synthesis of cyanamides and tetrazoles from isothiocyanates through tandem reaction using cobalt catalyst has been demonstrated. In the case of tetrazole preparation, the reaction involved addition/desulfurization/nucleophilic addition/electrocyclization, whereas aromatic cyanamides were constructed from isothiocyanates through addition/desulfurization. Cheap cobalt sulfate was used for the synthesis of various cyanamides and tetrazoles. In addition, cobalt catalyst was found to be desulfurization reagent that has not been previously reported. The final products have been obtained from starting precursors in good to high yield.
- Seelam, Mohan,Kammela, Prasada Rao,Shaikh, Bajivali,Tamminana, Ramana,Bogiri, Sujatha
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p. 535 - 544
(2018/07/05)
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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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- 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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- 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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- Bromineless bromine as an efficient desulfurizing agent for the preparation of cyanamides and 2-aminothiazoles from dithiocarbamate salts
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In a one-pot procedure, bromineless brominating reagent 1,1'-(ethane-1,2-diyl)dipyridinium bistribromide (EDPBT) has been used as a desulfurizing agent in the preparation of organic cyanamides and substituted thiazoles starting from dithiocarbamic acid salts. In this approach, alkyl/aryl isothiocyantes were first obtained by the desulfurization of dithiocarbamic acid salts with EDPBT. The in situ-generated isothiocyanates reacts with an aqueous ammonia, forming alkyl or aryl thioureas, which on subsequent oxidative desulfurization with EDPBT led to the formation of corresponding cyanamides in good yields. Alternatively, an efficient one-pot synthesis of substituted thiazoles has been achieved by the condensation of the in situ-generated 1-aryl thioureas with the in situ-generated -bromoketones from ketones, again using EDPBT. The reagent EDPBT can be easily prepared from the readily available reagents. Desulfurizing ability dominates over its brominating ability for substrates amenable to bromination.
- Yella, Ramesh,Kavala, Veerababurao,Patel, Bhisma K.
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experimental part
p. 792 - 805
(2011/04/22)
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- An efficient synthesis of cyanamide from amine promoted by a hypervalent iodine(III) reagent
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In a one-pot strategy we have achieved an efficient method for the synthesis of organic cyanamides starting from dithiocarbamic acid salts/amines. In this strategy the in situ generated alkyl or aryl isothiocyanates, obtained by the desulfurization of dithiocarbamic acid salts with diacetoxyiodobenzene (DIB) react with aqueous ammonia forming alkyl or aryl thiourea which on subsequent oxidative desulfurization with DIB led to the formation of corresponding cyanamide in good yields. Mild reaction conditions, shorter reaction time, an environmentally benign protocol, and easy isolation of the desired product make the present methodology a suitable alternative for the preparation of various organic cyanamides.
- Ghosh, Harisadhan,Yella, Ramesh,Ali, Abdur Rezzak,Sahoo, Santosh K.,Patel, Bhisma K.
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experimental part
p. 2407 - 2410
(2009/07/26)
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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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- A convenient and efficient method for the synthesis of mono- and N,N-disubstituted thioureas
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A convenient method for the synthesis of mono- and N,N-disubstituted thioureas by the debenzoylation of N-substituted- and N,N-disubstituted- N′-benzoylthioureas with hydrazine hydrate under solvent-free conditions has been developed. N-Substituted-N′-benzoylthioureas and hydrazine hydrate were mixed, and stirred at room temperature without a solvent to give the corresponding N-substituted thioureas in high yields.
- Kodomari, Mitsuo,Suzuki, Masato,Tanigawa, Keiko,Aoyama, Tadashi
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p. 5841 - 5843
(2007/10/03)
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- Substituted 5,5′-diphenyl-2-thioxoimidazolidin-4-one as CB 1 cannabinoid receptor ligands: Synthesis and pharmacological evaluation
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A set of 30 substituted 5,5′-diphenyl-2-thioxoimidazolidin-4-one (thiohydantoins) derivatives was synthesized, and their affinity for the human CB1 cannabinoid receptor has been evaluated. These compounds are derived from the previously described cannabinoid ligands 5,5′- diphenylimidazolidine-2,4-dione (hydantoins). The replacement of the oxygen by a sulfur leads to an increase of the affinity while the function-i.e., inverse agonism-determined by [35S]-GTPγS experiments remains unaffected. Finally, to evaluate the molecular parameters that could influence the affinity of the thiohydantoins, molecular electrostatic potential as well as lipophilicity calculations were undertaken on representative thiohydantoins and hydantoins derivatives. In conclusion, 5,5′-bis-(4-iodophenyl)-3-butyl-2- thioxoimidazolidin-4-one (31) and 3-allyl-5,5′-bis(4-bromophenyl)-2- thioxoimidazolidin-4-one (32) possess the highest affinity for the CB 1 cannabinoid receptor described to date for the hydantoin and thiohydantoins series when compared in a same bioassay.
- Muccioli, Giulio G.,Martin, Diana,Scriba, Gerhard K. E.,Poppitz, Wolfgang,Poupaert, Jacques H.,Wouters, Johan,Lambert, Didier M.
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p. 2509 - 2517
(2007/10/03)
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- Synthesis of mono- and N,N-disubstituted thioureas and N-acylthioureas
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1-Benzotriazole-1-carbothioamide (2), prepared from 1-cyanobenzotriazole (1) and hydrogen sulfide, reacts with amines to give thioureas 3a-e. Reactions of (benzotriazol-1-yl)carboximidamides 4a-d,f-j and acyl- 5a-f,i-k or arylaminocarbonyl- 5g,h (benzotri
- Katritzky, Alan R.,Kirichenko, Nataliya,Rogovoy, Boris V.,Kister, Jeremy,Tao, Hui
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p. 1799 - 1805
(2007/10/03)
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- 1,4,5-Trialkyl imidazole system anti-inflammatory properties of new substituted derivatives
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In an investigation of the anti-inflammatory properties of five-membered ring nitrogen-containing heterocyclic compounds, two series of derivatives of imidazole were prepared by altering the sites of substitution and by joining aliphatic chains to the nitrogen atom in the 1 position of the imidazole ring. Some of them were more potent inhibitors of carragenan-induced edema than indomethacin. An electron spin resonance study indicated that these compounds possess anti-radical activity.
- Fatimi,Lagorce,Duroux,Chabernaud,Buxeraud,Raby
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p. 698 - 701
(2007/10/02)
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- Synthesis and antithyroid activity of 1,4,5-trialkyl 2-thioimidazole derivatives
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A series of compounds based on the structure of MTI (1-methyl-2-thioimidazole) were synthesized by condensation of α-hydroxyketones and alkylthioureas. The α-hydroxyketones were obtained by a radical reaction in the presence of sodium and the alkyl ester, while the alkylthioureas were prepared by nucleophilic addition of ammonia on an alkylisothiocyanate. The antithyroid activity of the 13 compounds prepared was evaluated in vitro by determination of the concentrations which led to a 50% inhibition (IC50) of the activity of thyroid peroxidase, and in vivo by assay of thyroid hormones levels and histological examination of the thyroid gland in rats treated chronically with the compounds. 1-methyl-4,5-dipropyl 2-thioimidazole (compound 10) was found to have the highest antithyroid activity of the 13 compounds synthesized.
- Fatimi,Lagorce,Chabernaud,Comby,Buxeraud,Raby
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p. 253 - 257
(2007/10/02)
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- Synthesis and inhibitory effects of 1,4,5-trialkyl-2-thioimidazole derivatives on platelet aggregation
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New 1,4,5-trialkyl-2-thioimidazole have been synthesized by the condensation of α-hydroxyketones and alkylthioureas. The in vitro platelet aggregation inhibiting effect of prepared compounds on human platelets was studied in the presence of ADP and collagen as inducers. The formation of thromboxane B2 (TXB2) was inhibited. 1-isopropyl-4,5-dimethyl-2-thioimidazole has the greatest aggregation inhibiting effect, about 4 times that of aspirin. It highly inhibits the production of TXB2 (68,5% for a final concentration of 0,04 M).
- Fatimi,Lagorce,Chabernaud,Buxeraud,Raby
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p. 151 - 155
(2007/10/02)
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- Reduction of 1,2,4-thiadiazol-3-yl-thioureas: Formation of 1,3,5-triazine-2-thiones, 2,4-dithiones and amidinothioureas
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Reduction of thiadiazol-3-yl-thioureas (I) in alcoholic ammoniacal hydrogen sulphide furnish 1,3,5-triazine-2-thiones (III), 2,4-dithiones (VI) and/or amidinothioureas (VII) depending upon the substituents in I.
- Joshua, C. P.,Sujatha, T. S.
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p. 330 - 334
(2007/10/02)
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- Thermally induced transformations of 1-substituted-4,4,6-trimethyl-1,4-dihydropyrimidine-2(3H)-thiones
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Intramolecular thermal rearrangement of 1-substituted-4,4,6-trimethyl-1,4-dihydropyrimidine-2(3H)-thiones (1) to 4-substituted-amino-6,6-dimethyl-5,6-dihydropyridine-2(1H)-thiones (2), in molten state, constituting a unique Dimroth type rearrangement is reported.
- Singh, Harjit,Aggarwal, Pawan,Kumar, Subodh
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p. 740 - 743
(2007/10/02)
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