1194-57-6Relevant articles and documents
Temperature dependence of the reduction of phthalic thioanhydrides by NaBH4: Competition between 3-hydroxythiolactone and phthalide formation
Polec, Iwona,Lutsen, Laurence,Vanderzande, Dirk,Gelan, Jan
, p. 1033 - 1036 (2002)
The reduction of phthalic thioanhydrides with NaBH4 at between 0 and -20 °C leads to the selective formation of 3-hydroxy-2-thiophthalides, whereas higher temperatures favour the formation of the corresponding phthalide derivatives. A mechanism is proposed that can explain these observations. Kinetic control at low temperatures leads to an improved stability of the intermediate alkoxide, thus allowing isolation of the γ-hydroxythiolactone after subsequent acidification of the reaction mixture. In this way the formation of the thermodynamically favoured phthalide derivative is avoided. Further reduction of the y-hydroxythiolactone with AcOH/57% aqueous HI yields 2-thiophthalides, useful precursors for conducting polymers. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
Synthesis of benzothiophenones and naphthothiophenone as anticholinesterases
Jung
, p. 5325 - 5327 (2013)
Since AChE and BuChE belong to the same serine hydrolazes, we designed and synthesized compounds 1-6 as anticholinesterases and measured their inhibition poteucies on ChEs. 7-Methoxy-3H-benzo[c]thiophen-1-one 4, 4,6-dibromo-5,7- methoxy-3H-benzo[c]thiophe
Unexpected rearrangements in the synthesis of arylidene- or alkylidene-2-thiophthalides
Paulussen, Harald,Adriaensens, Peter,Vanderzande, Dirk,Gelan, Jan
, p. 11867 - 11878 (1996)
Mechanistic studies concerning the reaction by which poly(isothianaphthene) (PITN) is synthesized in one step from commercially available monomers by reacting them with phosphorus pentasulphide (P4S10), have led to the idea of synthesizing a chain-stopper molecule which should give rise to suitable quinoid model compounds for PITN. Within this context benzylidenedithiophthalide and pentylidenedithiophthalide were chosen as target molecules. The unexpected rearrangements and the control of these rearrangements in the synthesis of benzylidenedithiophthalide and pentylidenedithiophthalide are reported.
Synthesis of Disulfide-Bridged N-Phenyl-N′-(alkyl/aryl/heteroaryl)urea Derivatives and Evaluation of Their Antimicrobial Activities
Dilem Do?an, ?engül,Buran, Sümeyye,G?zde Gündüz, Miyase,?zkul, Ceren,Siva Krishna, Vagolu,Sriram, Dharmarajan
, (2019)
The discoveryof new antimicrobial agents is extremely needed to overcome multidrug-resistant bacterial and tuberculosis infections. In the present study, eight novel substituted urea derivatives (10a–10h) containing disulfide bond were designed, synthesized and screened for their in vitro antimicrobial activities on standard strains of Gram-positive and Gram-negative bacteria as well as on Mycobacterium tuberculosis. According to the obtained results, antibacterial effects of the compounds were found to be considerably better than their antimycobacterial activities along with their weak cytotoxic effects. Molecular docking studies were performed to gain insights into the antibacterial activity mechanism of the synthesized compounds. The interactions and the orientation of compound 10a (1,1′-((disulfanediylbis(methylene))bis(2,1-phenylene))bis(3-phenylurea)) were found to be highly similar to the original ligand within the binding pocket E. faecalis β-ketoacyl acyl carrier protein synthase III (FabH). Finally, a theoretical study was established to predict the physicochemical properties of the compounds.
A convenient synthesis of aromatic thiolactones
Pal,Murty,Mal
, p. 1555 - 1560 (1993)
Hydrolytic decomposition of thiouronium salts A with aqueous NaHCO3 at 80°-90°C directly furnished thiolactones 6-10 in very good yields in one-flask operation.
A new convenient method for preparation of condensed aromatic and heterocyclic thiolactones
Vegh,Morel,Decroix,Zalupsky
, p. 2057 - 2061 (1992)
Cyclocondensation of the benzylic-type thiols (Ib-VIb) in ortho position on aromatic and heteroaromatic carboxylic acids to form the corresponding thiolactones (Ic-VIc) can be effected with polyphosphate esters (PPE) in organic solvents in 75-90% yields.
Flash vacuum thermolysis of 4H-3,1-benzoxathiin-4-thione: UV-photoelectron spectroscopy characterization and quantum chemistry studies
Drewnowski, Tomasz,Chrostowska, Anna,Lesniak, Stanislaw,Dargelos, Alain,Khayar, Said
, p. 766 - 781 (2008)
The mechanism of the reaction of 4H-3,1-benzoxathiin-4-thione (3) under flash vacuum thermolysis conditions has been studied by UV-photoelectron spectra. It was shown that in the first step of the reaction at 400° 3 underwent the Schoenberg - Newman - Kwart rearrangement to give 4H-1,3-benzodithiin-4-one (6). Increasing of the temperature to 650° resulted in the elimination of thioformaldehyde and the formation of benzothiet-2-one (1). Subsequent elevation of the temperature prompted presumably the ring opening of 1 to (6-thioxocyclohexa-2,4-dien-1-ylidene) methanone (7) (at 680°), which at 700° eliminated CO and underwent a Wolff-type ring contraction to give (cyclopenta-2,4-dien-1-ylidene)methanethione (2). UV-Photoelectron spectra were recorded at different steps of the reaction and analyzed considering the theoretical evaluation of ionization potentials.
Studies on the flash vacuum thermolysis of thiones of selected N-, O-, and S-heterocycles
Drewnowski, Tomasz,Lesniak, Stanislaw,Mloston, Grzegorz,Siedlecka, Renata,Skarzewski, Jacek
, p. 991 - 999 (2006)
Thermal decomposition of thiones of selected N-, O- and S-heterocycles under flash vacuum thermolysis conditions was investigated. In the case of six-membered 4H-3,1-benzoxathiin-4-thione 6, the course of the reaction depended on the substitution pattern at C(2) (Scheme 3). Thus, the 2-unsubstituted derivative 6a led to the unstable product 2, which upon treatment with MeOH was converted quantitatively into methyl 2-mercaptobenzoate (7). The analogous thermolysis of the 2,2-dimethyl derivative 6b yielded 2-methyl-4H-1- benzothiopyran-4-thione (8) as a sole product. In the case of thiophthalide derivatives 15, a thermal rearrangement in the gas phase leading to the corresponding benzo[c]thiophen-1(3H)-ones 16 in high yields was observed (Scheme 6). Unexpectedly, thionation of 1,3-oxathiolan-5-one 17 with Lawesson's reagent under standard conditions led to 1,2-dithietane derivative 19, which, after the gas-phase thermolysis, underwent a ring enlargement to yield 3H-1,2-dithiole 20 (Scheme 7). The six-membered 4H-1,3-benzothiazine-4-thione 21 was shown to give three products: phenanthro[9,10-c]-1,2-dithiete (22), 3H-1,3-benzodithiole-3- thione (23), and N-(3H-1,2-benzodithiol-3-ylidene)prop-2-en-1-amine (24) (Scheme 8). The latter is the product of the initial reaction, whereas 22 and 23 are postulated to be formed as secondary products of the conversion of the intermediate 6-(thioxomethylene)cyclohexa-2,4-diene-1-thione (26) (Schemes 9 and 10).
The Hydrolysis of Phthalide, Thiophthalide, and Methyl o-Methoxybenzoate in Highly Alkaline Media. Curvature in the khyd vs Profile
Kellogg, B. A.,Brown, R. S.,McDonald, R. S.
, p. 4652 - 4658 (1994)
The hydrolyses of phthalide (2a) and thiophthalide (3) have been studied in highly alkaline media, T = 25 deg C, μ = 3 (KCl).For both esters, an upward curvature in the plot of khyd vs is observed, suggestive of the onset of a second order in process in the hydrolysis.Carbonyl 18O-exchange studies indicated that no 18O is lost from the ester recovered from the hydrolysis media at times up to 3t1/2 hydrolysis.Solvent kinetic isotope (skie) studies indicate that for 3, (khyd)H2O/D2O is inverse throughout the entire range of .The lack of 18O-exchange and the inverse nature of the skie on khyd suggest that the curvature in the khyd vs plots is not due to the involvement of two hydroxides in the hydrolytic process.A correlation of the khyd data with the acidity function H- appropriate for highly alkaline media is linear and suggests the involvement of a single hydroxide throughout the entire range.A reinvestigation of the alkaline hydrolysis of methyl o-methoxybenzoate (4) accompanied by 18O-exchange studies failed to detect unambiguous evidence for a bona fide second order in process.
Biomimetic systems involving sequential redox reactions in glycolysis-the sulfur effect
Ogawa, Narihito,Furukawa, Sei,Kosugi, Yuya,Takazawa, Takayuki,Kanomata, Nobuhiro
, p. 12917 - 12920 (2020)
Magnesium hemithioacetates were used as model cysteine compounds to mimic natural hemithioacetals, and their biomimetic oxidation reactions using a model NAD+ compound were investigated. Cyclic hemithioacetate was found to be the best substrate for the reaction with the model NAD+ compound, which gave the corresponding NADH analog in excellent yield. This journal is
