- Temperature-Controlled Chemoselective Synthesis of Thiosulfonates and Thiocyanates: Novel Reactivity of KXCN (X=S, Se) towards Organosulfonyl Chlorides
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An efficient chemoselective protocol has been developed for the synthesis of thiosulfonates and thiocyanates by employing cost effective and commercially available organosulfonyl chlorides with potassium thio-/selenocyanate. The strategy offered the thiosulfonates and thiocyanates selectively by tuning the equivalents of KSeCN and optimizing the reaction temperature. On the other hand, thiosulfonates were obtained as sole products when organosulfonyl chlorides were treated with KSCN. Furthermore, the syntheses of diarylthioethers and aryl(heteroaryl) thioethers were carried out as a part of synthetic application of newly prepared arylthiocyanates.
- Kalaramna, Pratibha,Goswami, Avijit
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supporting information
p. 5359 - 5366
(2021/10/25)
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- A pharmaceutical intermediate thiocyanate -2,4-disubstituted compound comprising hydroxy amidine or guanidine group method for the synthesis of (by machine translation)
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A pharmaceutical intermediate thiocyanate -2,4-method for synthesizing compound comprising hydroxy amidine or guanidine group, comprising the following steps: in mounting a stirrer, thermometer, reflux condenser in the reaction container, adding 2,4-dinitrobenzene (2) 0.32mol, cyclonexane 500 ml, stannous chloride 0.31mol, thiocyanogen methylamine solution 0.51-0.53mol, control the stirring speed 150-190rpm, to the temperature of the solution elevated 80-85°C, keep the backflow 5-7h, reducing the temperature of the solution to 5-9°C, separating the organic layer, the aqueous layer extracted with acetonitrile, combined with the organic layer, salt solution washing, ethylenediamin washing, dehydrating agent dehydration, nitromethane in the recrystallization, to obtain crystal thiocyanate -2,4-dinitrobenzene ester. (by machine translation)
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Paragraph 0015; 0016
(2016/11/21)
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- Improved procedure to aryl thiocyanates: A new synthetic application of dry arenediazonium o-benzenedisulfonimides
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Aryl thiocyanates 3 (22 examples) were easily prepared by reaction of dry arenediazonium o-benzenedisulfonimides 1 and sodium thiocyanate (2) in anhydrous acetonitrile at room temperature (20-25 °C) in the presence of copper powder (Procedure A) and at 50 °C or room temperature without the metal catalyst (Procedure B). The yields were from very good to excellent in Procedure A (average yield = 83%), and from modest to excellent in Procedure B (average yield = 63%). In comparison with the thiocyanod-ediazoniation carried out under traditional Sandmeyer-type conditions, the yields of 3 were higher and the isothiocyanate isomers were formed only in traces. Moreover, the results obtained in the absence of copper confirm the role of the anion of salts 1 as an electron transfer agent.
- Barbero,Degani,Diulgheroff,Dughera,Fochi
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p. 585 - 590
(2007/10/03)
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- Nucleophilic Aromatic Substitution promoted by Lipophilic Quaternary Onium Salts under Phase-transfer Conditions and in Low Polarity Anhydrous Solvents. A Kinetic Study
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A kinetic study of aromatic nucleophilic substitutions by N3(1-) and SCN(1-) has been carried out under phase-transfer catalysis (p.t.c.) conditions and in anhydrous chlorobenzene in the presence of hexadecyltributylphosphonium azide and thiocyanate.Under p.t.c. conditions, reactions follow a pseudo-first-order kinetic equation, and kobs is linearly related to the nucleophile concentration in the organic phase.In most reactions, the rate-determining step is attack by the nucleophile on the substrate.However in a few cases the process is controlled by diffusion ofthe anions through the interface.Passing from p.t.c. conditions to chlorobenzene solution leads to 5-7- and 2-3-fold increases in reaction rates with N3(1-) and SCN(1-), respectively.This behaviour is analogous to that observed in the aliphatic series, and is probably due to the limited number of water molecules accompanying the anions in the organic phase under p.t.c. conditions.Nucleofugicity scales are related to the polarizability of the nucleophile, and with N3(1-) and SCN(1-) they are F>>Br>=I>=Cl and Br>I>F>=Cl, respectively.Reaction products, including those derived from successive decomposition of N3 and SCN groups, have been identified.
- Landini, Dario,Maia, Angelamaria,Montanari, Fernando
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p. 461 - 466
(2007/10/02)
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