Kinetic characteristics of reactions of mercaptide ions of the ?-hydroxyethyl mercaptan-triethylamine system with olefin oxides at 15?45�C

Malievskii, A. D.; Gorbunova, O. I.

doi:10.1007/bf01474196

Cited by 2 publications

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“…For example, in the case of triethylamine, this assumption is based on the following facts. It was qualitatively established that when triethylamine is saturated with hydrogen sulfide, its electric conductivity increases; for the triethylamine--2-hydroxyalkane-l-thiol--epoxide system, the ionic character of the reaction was experimentally established; and the kinetic parameters were quantitatively determined for all its stagesfl [4][5][6][7][8][9][10][11][12][13][14][15][16][17] For quantitative comparison of the efficiency of catalytic additives at unchanged values of rate constants k" 4 = 2.1 9 10 -6 , k' 6 = 3.6-10 -4 , k" 7 = 1.7-10 -3 moi-2s -l, and k" 5 = 8.3. 10 -7 tool -t s -I, we chose the k" 3 values to obtain the maximum coincidence of the experimental and calculated kinetic curves.…”

Section: Resultsmentioning

confidence: 99%

Kinetic peculiarities of the reaction of liquefied hydrogen sulfide with propylene oxide

Malievskii

Shokina

1999

Russ Chem Bull

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The kinetics of the liquid-phase reaction of hydrogen sulfide with propylene oxide was studied. In the presence of excess epoxide, the reaction occurred in two successive macrostages: (1)formation of 2-hydroxypropane-l-thiol and (2)formation of l , l ' -d i ( 2 -hydroxypropyl) sulfide. Both of the stages are autocatalytic. 2-Hydroxypropane-l-thiol was mainly formed in the presence of excess H2S. The overall third order of the reaction (the first with respect to each reagent and to 2-hydroxypropane-l-thiol) was found. A kinetic scheme was proposed, and the rate constants of particular stages were calculated. The influence of various catalysts (active carbon, ion-exchange resins, metal oxides, and others) was studied, and the relative efficiency of some of them was determined.Key words: hydrogen sulfide, propylene oxide, catalysis, autocatalysis, kinetics, rate constants.Early works 1-6 on the reactions of hydrogen sulfide with epoxy c o m p o u n d s were mainly preparative. In some of t h e m , the effects o f temperature, solvent, and catalytic additives on these reactions were studied. The kinetics o f the reactions o f H2S with epoxy compounds was mainly studied using solvents that were not inert in these reactions. [4][5][6] This work is devoted to studying the kinetics and m e c h a n i s m of the previously found 7 reaction of hydrogen sulfide with propylene oxide (PO). The process was carried out without a solvent at temperature and pressure that allow the reagents to exist in the liquified state. The o c c u r r e n c e o f the reaction in the liquid phase in the absence o f solvents makes it possible to study in more detail the kinetics and m e c h a n i s m of the reaction and to observe all its peculiarities, including those that could not be observed in the presence of a solvent. ExperimentalThe reaction of liquefied H2S with PO was carried,out in an autoclave-type reactor with a magnetic stirrer. 8 Liquefied H2S and P O were loaded into the reactor. The reaction was carried out in an inert gas (nitrogen) atmosphere at 75 ~ and 75 arm. The moment of achievement of the needed temperature was taken as the beginning of reaction. Analysis of the critical temperatures and pressures of the reagents showed that the conditions of the reaction are determined by the critical parameters of hydrogen sulfide. 9.1~ A 2--3-mL sample for analysis was taken in a sampler, from which the liquid component moved to a measuring cell due to throttling, and the gas component moved to a gasometer. The liquid sample was analyzed for the content of PO and reaction products by GLC, and the content of H2S was determined using the volumetry method (a saturated solution of CuSO 4 was used as the absorbent). Triethylamine, potassium hydrosulfide, alcohol solutions of sodium and potassium ethylates, anion-exchange resin AV-17-8, strongly basic anion-exchange resin IOS-3, cation-exchange resin KU-2, iron and lead oxides, active carbon (dry alkaline, finely dispersed), and bidistilled water were used as catalytic additives. Results and...

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Section: Resultsmentioning

confidence: 99%

Kinetic peculiarities of the reaction of liquefied hydrogen sulfide with propylene oxide

Malievskii

Shokina

1999

Russ Chem Bull

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Mechanistic studies on the synthesis of bicalutamide

Asaad

Fillery

2009

Org. Biomol. Chem.

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Bicalutamide, a therapeutically important anti-androgen used in the treatment of hormone-sensitive cancers, may be synthesised from the appropriate halohydrin or epoxide. We report here studies aimed at demonstrating unambiguously that preparation of bicalutamide and its thioether analogue from the chlorohydrin under basic conditions proceeds via opening of an intermediate epoxide by the appropriate sulfinate or thiolate nucleophile, that the analogous anionic sulfur nucleophiles react under the same conditions and that the S(N)2 pathway involving direct displacement of chloride by the nucleophile does not operate. The proposed mechanism is confirmed by the quantitative fitting of sequential reaction kinetics, taking into account the competing dimerisation of the thiolate nucleophile that occurs under basic conditions. The O-methyl analogue of the chlorohydrin is unreactive towards thiolate under the same conditions, although a slower cyclisation to the beta-lactam was observed. The implications of these observations for the analogous preparation of thioethers and sulfones are discussed.

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Kinetic characteristics of reactions of mercaptide ions of the ?-hydroxyethyl mercaptan-triethylamine system with olefin oxides at 15?45�C

Cited by 2 publications

References 2 publications

Kinetic peculiarities of the reaction of liquefied hydrogen sulfide with propylene oxide

Kinetic peculiarities of the reaction of liquefied hydrogen sulfide with propylene oxide

Mechanistic studies on the synthesis of bicalutamide

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