10514-34-8Relevant academic research and scientific papers
Transition Metal-Free Synthesis of Substituted Isothiazoles via Three-Component Annulation of Alkynones, Xanthate and NH4I
Li, Jian,Li, Jiaming,Ji, Xiaoliang,Liu, Qiang,Chen, Lu,Huang, Yubing,Li, Yibiao
supporting information, p. 1059 - 1068 (2020/12/15)
A protocol was described to access diverse isothiazoles with functionalization potential via transition metal-free three-component annulation of alkynones, potassium ethylxanthate (EtOCS2K) and ammonium iodide (NH4I). A sequential regioselective hydroamination/thiocarbonylation/intramolecular cyclization cascade achieved the efficient formation of consecutive C?N, C?S and N?S bonds in a one-pot process. (Figure presented.).
3, 5-disubstituted isothiazole compound and synthesis method and application thereof
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Paragraph 0157-0162, (2021/03/30)
The invention belongs to the technical field of organic synthesis, and discloses a 3, 5-disubstituted isothiazole compound and a synthesis method and applications thereof, the structural formula of the compound is represented by formula (II), and R1 and R2 respectively and independently represent hydrogen, a heterocyclic group, phenyl, a phenyl derivative or alkane. According to the invention, the3, 5-disubstituted isothiazole compound is synthesized by taking the acetylenic ketone compound as a raw material, heating and stirring under the condition of adding a solvent and carrying out one-pot reaction without catalysis of transition metal, and the synthesis is completed in one step without separating and purifying an intermediate in a conversion process except for a final product, so that industrial production is easy to realize, and capital and labor investment can be reduced for industrial production.
Microwave-induced generation and reactions of nitrile sulfides: An improved method for the synthesis of isothiazoles and 1,2,4-thiadiazoles
Fordyce, Euan A.F.,Morrison, Angus J.,Sharp, Robert D.,Paton, R. Michael
experimental part, p. 7192 - 7197 (2010/10/01)
The 1,3-dipolar cycloaddition reactions of nitrile sulfides, generated by microwave-assisted decarboxylation of 1,3,4-oxathiazol-2-ones, have been investigated. By this approach ethyl 1,2,4-thiadiazole-5-carboxylates 3 were prepared in good yield by cycloaddition of the nitrile sulfides to ethyl cyanoformate. Similarly, reaction of benzonitrile sulfide with dimethyl acetylenedicarboxylate (DMAD) afforded dimethyl 3-phenylisothiazole-4,5- dicarboxylate (5). In contrast, o-hydroxybenzonitrile sulfide, generated from the corresponding oxathiazolone 2d, reacted with DMAD to give methyl 4-oxo-4H-[1]benzopyrano[4,3-c]isothiazole-3-carboxylate (8) in high yield. A ca. 1:1 mixture of ethyl 3-phenylisothiazole-4- and 5-carboxylates (6,7) was formed from benzonitrile sulfide and ethyl propiolate. The corresponding reaction with diethyl fumarate gave diethyl trans-4,5-dihydro-3-phenylisothiazole-4,5- dicarboylate (10). 3-Arylisothiazoles, unsubstituted at both the 4- and 5-positions, were prepared from the reaction of 5-aryl-1,3,4-oxathiazolones with norbornadiene by a pathway involving cycloaddition of the nitrile sulfide to the norbornadiene, followed by retro-Diels-Alder extrusion of cyclopentadiene from the resulting isothiazoline cycloadduct 12. In summary, the use of microwave irradiation, rather than conventional heating methods, allows nitrile sulfide generation and reactions to be carried out in shorter times, with easier work-up and, in some cases, in higher yields.
Photochemistry of 3- and 5-phenylisothiazoles. Competing phototransposition pathways
Pavlik, James W.,Tongcharoensirikul, Pakamas
, p. 3626 - 3631 (2007/10/03)
5-Phenylisothiazole undergoes phototransposition via the electrocyclic ring closure-heteroatom migration pathway and by the N2-C3 interchange reaction pathway. The latter route is enhanced by the addition of triethylamine (TEA) to the reaction medium and by increasing the polarity of the solvent. In addition to phototransposition, 5-phenylisothiazole also undergoes photocleavage to 2-cyano-1-phenylethenethiol which was trapped by reaction with benzyl bromide to yield 2-cyano-1-phenylethen-1-ylbenzyl thioether. 3-Phenylisothiazole also phototransposes by both reaction pathways, but the product distribution is not affected by the addition of TEA or by changing the solvent polarity.
Phototransposition chemistry of phenylisothiazoles and phenylthiazoles. 1. Interconversions in benzene solution
Pavlik, James W.,Tongcharoensirikul, Pakamas,Bird, Nigel P.,Day, A. Colin,Barltrop, John A.
, p. 2292 - 2300 (2007/10/02)
Phenylthiazoles 1-3 and phenylisothiazoles 4-6 undergo phototransposition in benzene solvent mainly by P5, P6, and P7 permutation pathways. Phenylisothiazoles 5 and 6 also transpose via a P4 permutation process to yield phenylthiazoles 2 and 3 in less than 1% yield. In benzene saturated with D2O, 2-phenylthiazole (1) and 5-phenylisothiazole (6) each phototranspose to yield 4-deuterio-3-phenylisothiazole (4-D-4) and 4-phenylthiazole (2) without deuterium incorporation. Irradiation of 4-phenylthiazole (2) under these conditions results in rapid photodeuteration to yield 2-deuterio-4-phenylthiazole (2-D-2), which subsequently phototransposes to 5-deuterio-3-phenylisothiazole (5-D-3). These experimental results can be rationalized by a mechanism involving initial electrocyclic ring closure and sigmatropic shift of sulfur around the four sides of the azetine ring. Rearomatization of each bicyclic intermediate thus allows sulfur to insert into each position in the carbon-nitrogen sequence. As a consequence, these compounds divide into a tetrad in which isomers 1, 2,4, and 6 interconvert mainly via P5, P6, and P7 pathways and a dyad of two compounds in which 3 phototransposes to 5 via P5 and P7 pathways. Within the tetrad, BC-6, the bicyclic intermediate derived from 5-phenylisothiazoles (6), is postulated to undergo deuteration with simultaneous sigmatropic shift of sulfur when the reaction is carried out in benzene-D2O. This mechanistic view provides one coherent interpretation for the observed phototransposition and photodeuteration reactions.
Nitrile Sulphides. Part 9. Synthesis of 3-Arylisothiazoles
McKie, Marion C.,Paton, R. Michael
, p. 2051 - 2066 (2007/10/02)
3-Arylisothiazoles, unsubstituted at both 4- and 5-positions, have been prepared by two methods based on nitrile sulphide chemistry.Nitrile sulphides, generated by thermal decarboxylation of 5-aryl-1,3,4-oxathiazol-2-ones, react with norbornadiene to give 3-arylisothiazoles in one step, the best yields (50-80percent) being achieved under conditions of high dilution.The mechanism is believed to involve 1,3-dipolar cycloaddition to give dihydroisothiazole (6) followed by retro-Diels Alder extrusion of cyclopentadiene.With norbornene itself exo-dihydroisothiazole (8) is formed. 3-Arylisothiazoles also result from flash vacuum pyrolysis of 3-arylisothiazole-4- and 5-carboxylates and 4,5-dicarboxylates which are, respectively, the cycloadducts of nitrile sulphides with ethyl propiolate and diethyl acetylenedicarboxylate.
THE REACTIONS OF ISOTHIAZOLIUM SALTS WITH NITROGEN NUCLEOPHILIC REAGENTS
Hassan, Mohamed E.,Magraby, M. A.,Aziz, Magda A.
, p. 1885 - 1892 (2007/10/02)
Isothiazolium salts were allowed to react with a number of nitrogen nucleophiles including ammonia, hydrazine, phenylhydrazine, hydroxylamine, and benzylamine.The products obtained suggest that the position of initial nucleophilic attack is at the sulphur
