- 1-Alkyl-4-ethoxythiocarbonyl-5-hydroxy-3-methylpyrazole: Synthesis, copper complexes and solvent extraction studies
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1-Alkyl-4-ethoxythiocarbonyl-5-hydroxy-3-methylpyrazole, HETCP, (alkyl = n-octyl ; n-dodecyl) were prepared in high yield by the reaction of 1-alkyl-3-methyl-2-pyrazolin-5-one with bis (ethoxythiocarbonyl)sulfide and sodium acetate in dimethylformamide. These reagents act as O, S bidentate ligands in solvent extraction/reextraction studies of Cu (II) from acid aqueous solutions and the extracted specie resulted to be Cu(ETCP)2.
- Oliva, Alfonso,Molinari, Aurora,Toro, Carolina
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experimental part
p. 329 - 335
(2009/05/31)
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- 2-Chloro-4,5-dihydroimidazole. Part VII. Reactions with Carbon Disulfide and Potassium O-Alkyl Dithiocarbonates. Synthesis and Transformations of 2,3,7,8-tetrahydro-5H-diimidazothiadiazine-5-thione
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2-Chloro-4,5-dihydroimidazole 1 reacted with carbon disulfide to give 2,3,7,8-tetrahydro-5H-diimidazothiadiazine-5-thione 5.Acid hydrolysis of 5 gave imidazoline-2-thione 6, which reacted with amines, dialkylhydrazines, and alkoxides to give thioureas 9, thiosemicarbazides 10 and thiocarbamates 11, respectively.Reaction of the hemisulfate of 1 with excess of potassium O-alkyl dithiocarbonates afforded diesters of thiodicarbonic acid 13.
- Saczewski, Franciszek,Gdaniec, Maria
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- Kinetics and Mechanism of the Reactions of S-Ethoxycarbonyl O-Ethyl Dithiocarbonate with O-Ethyl Xanthate and O-Ethyl Thiocarbonate Ions
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The forward and back reactions of S-ethoxycarbonyl O-ethyl dithiocarbonate (1) with O-ethyl thiocarbonate (4) and O-ethyl xanthate (5) in 95percent ethanol are studied kinetically.The back reaction products are bis(ethoxycarbonyl) sulfide (3) with 5 and bis(ethoxythiocarbonyl) sulfide (2) with 4, respectively.Compound 1 reacts faster than 2 with 4, which means that the carbonyl group is more reactive than the thiocarbonyl toward 4.On the other hand, the reaction of 5 with 1 is faster than that with 3, which indicates that 5 reacts more readily with the thiocarbonyl than the carbonyl group.Two mechanisms are proposed to account for the kinetics results: one through tetrahedral intermediates (two-step reactions) and the other concerted.The reactions of 4 exibit ΔS >0, whereas those of 5 show ΔS 0.These ΔS values are explained by a larger solvation of 4 relative to 5 and similar degrees of solvation of transition states and substrates.The observed activation parameters do not allow discrimination between the two mechanisms.
- Castro, Enrique A.,Meneses, Beatriz,Santos, Jose G.,Vega, Juan C.
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p. 1863 - 1866
(2007/10/02)
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- PYROTHIOCARBONATES I. AMINOLYSIS OF S-(ETHOXYCARBONYL) O-ETHYL DITHIOCARBONATE
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The reaction of S-(ethoxycarbonyl) O-ethyl dithiocarbonate (1) with equimolar amounts of butylamine, benzylamine, diethylamine and piperidine in ethanol solution at 0 deg C is reported.The mole ratio of O-ethyl thiocarbamate (2) and O-ethyl carbamate (3) formed as main products is larger than unity during all the reaction.Bis(ethoxythiocarbonyl) sulfide (4) and bis(ethoxycarbonyl) sulfide (5) are also produced and their formation is explained in terms of the reaction of 1 with EtOCS2- and EtOCOS-, respectively, which are the leaving groups in the aminolysis of 1.Reactions 4 -> 2 and 5 -> 3 also take place.When 50percent of 1 has been consumed compound 4 is not detected and compound 5 is found at very low concentration, indicating that generation of 4 and 5 occurs mainly after aminolysis of 1.The fact that the ratio of 2 : 3 is larger than unity in this aminolysis step, and that S-methyl O-ethyldithiocarbonate is aminolyzed more readily than S-methyl O-ethylmonothiocarbonate under the same conditions as the aminolysis of 1, suggests that the thiocarbonyl group of 1 is more reactive than the carbonyl group.
- Palominos, Mario A.,Santos, Jose G.,Valderrama, Jaime A.,Vega, Juan C.
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p. 245 - 252
(2007/10/02)
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- Pyrothiocarbonates. Part 2. Reaction of S-Ethoxycarbonyl O-Ethyl Dithiocarbonate with some Potassium O-Alkylthiocarbonates
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The thiolysis of S-ethoxycarbonyl O-ethyl dithiocarbonate (1) has been examined in order to study both its transesterification reaction and the reactivities of its carbonyl and thiocarbonyl groups.The two symmetrical pyrothiocarbonates (EtOCS)2S (4) and (EtOCO)2S (5) are produced by reactions of (1) with EtOCS2K (7) or EtOCOSK (8) in 95percent ethanol at 0 deg C; (4) was always the main product in the reaction with (7) whereas (5) was initially the main product in the reaction with (8).The reaction of (1) with BuOCS2K yielded first BuOCS2CSOEt and then BuOCS2CO2Et and (BuOCS)2S.These results indicate that the thiocarbonyl group of (1) is more reactive than the carbonyl one.
- Palominos, Mario A.,Santos, Jose G.,Valderrama, Jaime A.,Vega, Juan C.
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p. 2641 - 2643
(2007/10/02)
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- Thiacyanocarbons. 5. Reactions of Tetracyano-1,4-dithiin and Tetracyanothiophene with Nucleophiles: Synthesis of Tetracyanopyrrole and Tetracyanocyclopentadiene Salts
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Reactions at the double bonds of tetracyano-1,4-dithiin and tetracyanothiophene have been explored.Generally, nucleophiles attack the dithiin by an addition-elimination mechanism to produce divinyl sulfides.The resulting anions are stable, experience fragmentation, or undergo further condensation reactions to produce heterocyclic structures.For example, tetracyano-1,4-dithiin is converted by thiocyanate ion to a thiophenopyrimidine.In fragmentation reactions, the dithiin acts as a masked maleonitrile and as such is useful for the synthesis of tetracyanoethylene.Remarkably, the dithiin reacts with sodium azide to give tetracyanopyrrole and with reactive methyl compounds to give substituted tetracyanocyclopentadienide ions.Tetracyanothiophene reacts with nucleophiles in a manner similar to tetracyanodithiin but at higher temperatures.
- Simmons, H. E.,Vest, R. D.,Vladuchick, S. A.,Webster, O. W.
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p. 5113 - 5121
(2007/10/02)
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