63348-55-0Relevant academic research and scientific papers
Iodine-promoted direct thiolation (selenylation) of imidazole with disulfides (diselenide): A convenient and metal-free protocol for the synthesis of 2-arylthio(seleno)imidazole
Yi, Rongnan,Liu, Sen,Gao, Hongxia,Liang, Zhiwu,Xu, Xinhua,Li, Ningbo
, (2020/02/05)
A convenient and metal-free protocol for the synthesis of 2-arylthio(seleno)imidazoles from imidazoles and disulfides (diselenides) was developed through the direct thiolation (selenylation) of imidazoles promoted by 0.5 equiv. of iodine. This process is
Studies on the reactive species in fluoride-mediated carbon-carbon bond-forming reactions: Carbanion formation by desilylation with fluoride and enolates
Biddle, Margaret M.,Reich, Hans J.
, p. 4031 - 4039 (2007/10/03)
The reactive species in fluoride-mediated carbon-carbon bond-forming reactions was investigated. The regio- and diastereoselectivities of silanes reacting with cyclohexenone in the presence of a catalytic amount of fluoride was compared to the reactivity of analogous solvent-separated lithium ion pairs. Closely analogous behavior was observed, showing that carbanions and not siliconate complexes are the reactive species in the fluoride-catalyzed reactions. Spectroscopic investigations unambiguously show that phenylthiobenzyl anion will form by reaction of silane with tris(dimethylamino)sulfonium difluorotrimethylsilicate (TASF) or crypt[2.1.1]-solvated lithium enolates. The catalytic cycle runs smoothly with the crypt[2.1.1] complex of α-(phenylthio)benzyllithium as the initiator and enolate as the carrier of the desilylation reaction.
Anti-thyroid drugs and thyroid hormone synthesis: Effect of methimazole derivatives on peroxidase-catalyzed reactions
Roy, Gouriprasanna,Mugesh
, p. 15207 - 15217 (2007/10/03)
Syntheses and characterization of the selenium analogue (MSeI) of anti-thyroid drug methimazole and a series of organoselenium compounds bearing N-methylimidazole pharmacophore are described. In contrast to the sulfur compound that exists predominantly in its thione form, the selenium analogue exists in a selenol form, which spontaneously oxidizes in air to produce the corresponding diselenide. The reduction of the diselenide by GSH or NaBH 4 affords the biologically active selenol, which effectively inhibits the lactoperoxidase (LPO) activity in vitro. The monoselenides having N-methylimidazole moiety are found to be much less active than the selenol, suggesting that the presence of a selenol moiety is important for the LPO inhibition. The kinetic and mechanistic studies reveal that MSeI inhibits the LPO activity by reducing the H2O2, providing a novel method to reversibly inhibit the enzyme. Although MSeI strongly inhibits LPO, the enzyme's activity can be completely recovered by increasing the H 2O2 concentration. On the other hand, the inhibition by methimazole (MMI), the sulfur analogue, cannot be reversed by increasing the H2O2 concentration, leading to a complete inactivation of the enzyme. The reversible inhibition of LPO by some of the selenium derivatives is correlated with their glutathione peroxidase (GPx) activity, and the high GPx activity of the selenium compounds as compared with their sulfur analogues suggests that the selenium derivatives may protect the thyroid gland from oxidative damage.
Preparation of 5-Substituted 2-Mercapto-1-methylimidazoles. Direct Metalation of 2-Mercapto-1-methylimidazole
Phillips, Brian T.,Claremon, David A.,Varga, Sandor L.
, p. 761 - 763 (2007/10/02)
2-Mercapto-1-methylimidazole (1) is directly metalated with tert-butyllithium in tetrahydrofuran to give the 5,S-dianion 2.Reaction of the dianion 2 with a series of electrophiles gives regioselectively 5-substituted 2-mercapto-1-methylimidazoles 4, 5 and
Benzylation of Thioamides and Thioureas with Triethylbenzylammonium Chloride Under Phase Transfer Catalysis
Singh, Paramjit,Aggarwal, Sunil K.,Sarin, Rakesh,Malhotra, Nageshwar,Singh, Harjit
, p. 263 - 265 (2007/10/02)
The reactions of triethylbenzylammonium chloride with thioamides/thioureas under phase transfer catalysis conditions provide mainly S-benzylated products.The reactions have been rationalised and optimum condition worked out to get the maximum yield of the
Nitroimidazoles: Part IV - 1-Sulphonyl(carbamoyl/thiocarbamoyl)-3-(1-methyl-5-nitroimidazol-2-yl)-2-imidazolidinones
Nagarajan, K.,Arya, V. P.,George, T.,Sudarsanam, V.,Shah, R. K.,et al.
, p. 928 - 940 (2007/10/02)
Sulphone (5) is condensed with sodium salts of a variety of 1-suplphonyl (7), 1-thiocarbamoyl (9) and 1-carbonyl (10)-2-imidazolidinones to give 3-(2-imidazolyl)imidazolidinones (12), (13) and (14) respectively, out of which 1-methylsulphonyl-3-(1-methyl-5-nitro-imidazol-2-yl)-2-imidazolidinone (12a) is undergoing clinical trials as an antiamoebic-antitrichomonal agent. 15 and 16 are analougous imidazolidinones, while 17 and 18 are benzimidazolone derivatives.The reaction of 5 with the sodium salt of 2-imidazolidinone gives rise to the mono and bis-condensation products 21 and 22 respectively.Several other minor byproducts, 23-27 have been identified. 23, 26 and 27 arise from 21. 24, a transformation product of 5 leads to the ether 25 by a displacement reaction.A second synthesis of 12a involves the nitration of imidazolylimidazolidinone (30) in the terminal step, with 30 becoming available from 1-methyl-2-aminoimidazole (28) and chloroethyl isocyanate, and subsequent reaction of resultant 29 with methanesulphonyl chloride.The higher ring homologue, 33 of 12a is synthesised in poor yield from 5 and 1-methylsulphonylhexahydropyrimidinone.Treatment of 12a and 13a with KI in DMF leads to the isomeric 4-nitro derivatives 38a, b and desmethyl derivates 37a, b.Treatment of 12a with triethyloxonium fluoroborate affords the quaternary isothiourea (35) which is hydrolysed to 36.Treatment of 12a and 13a with aqeous alkali leads to cleavage of imidazolidinone ring to form the ethylenediamines 31a and b.Position isomers 41 and 43 of 12a are respetcively obtained by the reaction of 1-methyl-4-nitro-5-chloro-(40)-, and 1-methyl-5-nitro-4-chloro-(42)-imidazoles with 1-methylsulphonyl-ethylene urea.Treatment of the last compound with various reactive halides, e.g. 2-chlorobenzothiazole, yields several analogues 44a-i of 12a while niridazole (45) and methylsulphonyl chloride affords nitrothiazole analogue 46.
PHOTOCHEMISTRY OF AZOLES, PART VII. PHOTOSOLVOLYSIS OF ALKYLMERCAPTOAZOLES. AN APPLICATION TO SOME ACYCLIC MONOTERPENE DERIVATIVES
Iwasaki, Shigeo
, p. 125 - 138 (2007/10/02)
Salts derived from 2-alkylmercapto-1-methylimidazoles 1b-e and 3-alkylmercapto-4-methyl-1,2,4-triazoles 2b-d have been found to undergo photochemical heterolytic fission of the S-alkyl bond in aqueous or methanolic solution to give solvolysis-type products.
