- Investigations of the Thermal Responsiveness of 1,4,2-Oxathiazoles
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The first systematic study of the thermal rearrangement/fragmentation of 5,5-disubstituted 1,4,2-oxathiazoles into isothiocyanates is reported. Structure-activity relationships reveal that the choice of substituent at the 5-position of the 1,4,2-oxathiazoles is the predominant factor to influence the ease of fragmentation.
- Hewitt, Russell J.,Ong, Michelle Jui Hsien,Lim, Yi Wee,Burkett, Brendan A.
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supporting information
p. 6687 - 6700
(2015/10/29)
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- PROCESS FOR PREPARING MERCAPTOALKYL CARBOXYLATES
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In the acid-catalyzed esterification of mercaptoalkyl alcohols by means of carboxylic acids to form mercaptoalkly carboxylates, formation of undesirable, usually sparingly soluble by-products usually occurs. The process of the invention in the absence of acid catalysts avoids the formation of such by-products. Particularly when the esterification of the invention is carried out as reactive distillation using reactive column and residence vessel, good degrees of conversion can also be obtained without acid catalyst and at the same time the formation of the by-products can be largely avoided.
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Paragraph 0049-0053
(2013/08/28)
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- Zinc promoted convenient and general synthesis of thiol esters
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Synthesis of thiol esters from acyl chlorides and thiols in the presence of activated zinc is described. The recovery of zinc and its reuse makes the procedure more economic.
- Meshram,Reddy, Gondi Sudershan,Bindu, K. Hima,Yadav
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p. 877 - 878
(2007/10/03)
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- ACTIVITY OF 1-OXA-3-THIACYCLOALKANES AND 2-ALKYLTHIOOXACYCLANES IN FREE-RADICAL ISOMERIZATION
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It was established that radical isomerization to alkyl esters of thiocarboxylic acids, initiated by tert-butyl peroxide at 130-150 deg C, is a common reaction for five-, six- and seven-membered 1-oxa-3-thiacycloalkanes and 2-alkylthiooxacycloalkanes.Under analogous conditions 2-diethylaminotetrahydropyran isomerizes to N,N-diethylvaleramide.The relation between the structure and the reactivity of 1-oxa-3-thiacycloalkanes and 2-alkylthiooxacycloalkanes in free-radical isomerisation was studied by the method of competing reactions.Depending on the ring size, the activity of the 1-oxa-3-thiacycloalkanes increases in the order : 1,3-oxathianes 1,3-oxathiolanes 1,3-oxathiepanes.
- Zorin, V. V.,Batyrbaev, N. A.,Zlot-skii, S. S.,Rakhmankulov, D. L.
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p. 347 - 352
(2007/10/02)
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- Acid-Catalyzed Hydrolysis of Ketene Dithioacetals and Trithioorthocarboxylates. Effect of β-Methyl Substitution
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Hydrolysis rates of β-methyl-substituted ketene dithioacetals were measured. β-Monomethyl and β,β-dimethyl substitutions reduced the reactivity of the parent acetal by factors of 26 and 6.7 x 105, respectively.Similar methyl substitutions of trithioorthoacetate, however, enhanced the hydrolysis reactivity by 3 and 23 times.The reversibility of protonation of ketene dithioacetal during hydrolysis was slightly increased by a β-methyl group, but dimethyl substitution seemed to inhibit reversibility by raising the potential barrier to protonation.
- Okuyama, Tadashi,Kawao, Shoji,Fueno, Takayuki
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