Kyongtae Kim

Synthesis and Reactions of 1,2,3-Dithiazoles

Abstract The synthesis and the reactions of 5-arylimino-4-chloro-5H-1,2,3-dithiazoles, 4-chloro-1,2,3-dithiazole-5-thione, 4-chloro-1,2,3-dithiazol-5-one, 4-chloro-5,5-difluoro-5H-1,2,3-dithiazole, 5-alkylidene-5H-1,2,3-dithiazoles, 4,5-dialkyl-5H-1,2,3-dithiazoles, some 1,2,3-dithiazolium ions and 1,2,3-dithiazolyl radicals are critically discussed. Emphasis has been placed on the mechanistic interpretation of these reactions. Applications of 1,2,3-dithiazoles are also included.

A short synthesis of quinazolinocarboline alkaloids rutaecarpine, hortiacine, euxylophoricine A and euxylophoricine D from methyl N-(4-chloro-5H-1,2,3-dithiazol-5-ylidene)anthranilates

Abstract Reactions of methyl N -(4-chloro-5 H -1,2,3-dithiazol-5-ylidene)anthranilates with tryptamine at room temperature produced 2-cyano-3-[2-(indol-3-yl)ethyl]-4(3 H )-quinazolinones, which underwent cyclization on heating with TFAA/HCl(g) to afford quinazolinocarboline alkaloids rutaecarpine ( 1a ), hortiacine ( 1b ), euxylophoricine A ( 1c ) and euxylophoricine D ( 1d ) in excellent yields.

Reactions of 5-arylimino-4-chloro-5H-1,2,3-dithiazoles with stable phosphoranes: Novel preparation of dithiomethylenephosphoranes

Abstract The reactions of 5-arylimino-4-chloro-5H-1,2,3-dithiazoles with 2 equivalents of stable phosphoranes such as carboethoxymethylene-, acetylmethylene-, 4-chlorobenzoylmethylene-, and cyanomethylenetriphenylphosphoranes in the presence of pyridine in CH 2 Cl 2 at room temperature gave a new type of the corresponding phosphoranes with aryliminocyanomethyldithiomethylene moiety as a major product.

4-Chloro-5H-1,2,3-dithiazol-5-one: a good α-thiocyanating agent for α,β-unsaturated β-amino esters

Abstract Treatment of 4-chloro-5 H -1,2,3-dithiazol-5-one with 3-alkyl (or aryl)-3-amino-2-propenoate esters in DMSO at 120°C gave the corresponding 2-thiocyanated esters 4 (major) and 5-alkoxycarbonyl-4-alkyl (or aryl)-4-thiazolin-2-ones 5 (minor), whereas the esters bearing a strong electron-withdrawing group at C-3 under the same conditions afforded 5 and/or 4-substituted 5-alkoxycarbonyl-2-aminothiazoles 6 , depending on the electron-withdrawing groups.

A Novel Method for the Synthesis of 2,3-Benzo-1,3a,6a-triazapentalenes through Pummerer-Type Reactions of γ-(Benzotriazol-1-yl)allylic Sulfoxides

Treatment of 1-(arylmethyl)benzotriazoles 1 with nBuLi in THF at −78 °C, followed by addition of 1-aryl-2-chloroethanones, gave diastereomeric mixtures of 1-[(aryl)(benzotriazol-1-yl)methyl]oxiranes 2. Treatment of 2 with nBuLi in THF at −78 °C, followed by acidification, afforded a mixture of (E)- and (Z)-allylic alcohols 3, which were converted into 1,2-disubstituted 2-(alkyl- or aryl)-1-(benzotriazol-1-yl)-3-sulfanylpropenes 5 via the corresponding allylic chlorides 4. Oxidation of sulfides 5 by mCPBA in CH2Cl2 at room temperature, followed by treatment with trifluoroacetic anhydride (TFAA) at room temperature, gave the title compounds in good yields. It was found that treatment of the title compounds with Raney-Ni in EtOH under hydrogen at reflux gave 2-(pyrazol-1-yl)aniline derivatives in excellent yields.

Synthesis of new5-alkylidene-4-chloro-5H-1,2,3-dithiazoles and their stereochemistry

Abstract A variety of5-alkylidene-4-chloro-5H-1,2,3-dithiazoles (9–25) have been prepared from4-chloro-5H-1,2,3-dithiazolium chloride, active methylene compounds, and pyridine. The reactions with ethyl nitroacetate ((Z) > (E)), ethyl 3-nitrobenzoylacetate ((E) > (Z)), ethyl 2-fluorobenzoylacetate ((E) > (Z)), and tetronic acid ((Z) > (E)) gave a mixture of(E)-and(Z)-isomers, whereas those of benzoylnitromethane (Z),5,6-dihydro-4-hydroxy-6-methyl-2H-pyran-2-one (E), 4-hydroxy-6-methyl-2-pyrone (E), 4-hydroxycoumarin (E), 6-chloro-4-hydroxycoumarin (E), and 6-bromo-4-hydroxycoumarin (E) afforded only single stereoisomers. The reactions with4-hydroxy-1-methyl-2(1H)-quinolone, 2-hydroxy-1,4-naphthoquinone and homophthalic anhydride gave only single stereoisomers whose stereochemistry is uncertain. It appears that geometrically more rigid cyclic 1,3-dicarbonyl compounds give better yields of dithiazol-5-ylidenes than the corresponding acyclic compounds. Download : Download full-size image

Reactions of 4-chloro-5H-1,2,3-dithiazol-5-thione with primary and secondary alkylamines: Novel method for preparing N-alkyl- and N,N-dialkylcyanothioformamides

Treatment of 4-chloro-5H-1,2,3-dithiazol-5-thione with primary and secondary alkylamines in CH2Cl2 at room temperature afforded N-alkyl- and N,N-dialkylcyanothioformamides, respectively.

Novel preparation of N′-arylthiocarbamoyl-N,N-dialkylamidines and their synthetic utilities

Abstract Treatment of 5-(arylimino)-4-(dialkylamino)-5H-1,2,3-dithiazoles (2) with NaOH in aqueous EtOH at room temperature gave N′-arylthiocarbamoyl-N,N-dialkylamidines (3) in good to excellent yields. The reaction of 3 with sulfur monochloride, thiophosgene, thionyl chloride, sulfuryl chloride, N-phenylimidoyl dichloride, and phthaloyl chloride in CH2Cl2 gave 2, 5-(arylimino)-4-(dialkylamino)-Δ3-thiazoline-2-thiones (5), 5-(arylimino)-4-(dialkylamino)-5H-2-oxo-1,2,3-dithiazoles (6), 5-(arylimino)-4-(dialkylamino)-5H-2,2-dioxo-1,2,3-dithiazoles (7), 5-(arylimino)-4-(dialkylamino)-2-(phenylimino)-Δ3-thiazolines (8), and 3-(arylimino)-4-(dialkylamino)-2,5-benzothiazocine-1,6-diones (10) as major products, respectively.

A facile synthesis of N′-(p-toluenesulfonyl)-N-alkyl- and N,N-dialkylcyanoformamidines and 1,3-dialkyl-2-(p-toluenesulfonyl)guanidines

Abstract Reactions of 4-chloro-5-(p-toluenesulfonylimino)-5H-1,2,3-dithiazole ( 2 ) with primary and secondary amines in CH 2 Cl 2 at room temperature gave N′-(p-toluenesulfonyl)-N-alkyl-and N,N-dialkylcyanoformamidines ( 3 ) (53–79% yields), respectively. Refluxing of 3 with secondary amines in CH 2 Cl 2 gave 1,3-dialkyl-2-(p-toluenesulfonyl)guanidines ( 7 ) (40–99% yields), some of which ( 7a, 7c ) were also directly obtained from the reactions of 2 with the corresponding amines without using the solvent.

A convenient synthesis of bis(o-arylmercaptophenyl)sulfides

Abstract Reactions of 5-arylthianthrenium perchlorates with arylthiolates in tetrahydrofuran at ambient temperature under nitrogen atmosphere afforded bis(o-arylmercaptophenyl)sulfides in excellent yields.