Reaction with dithiocarboxylic acids

This method is not general and only a limited number of 5-alkyl-l,2,3,4-thiatriazoles were prepared by this reaction. Ikeda and co-workers have described a convenient method for the synthesis of both 5-alkyl- and 5-aryl-l,2,3,4-thiatriazoles 9 by reaction of l-methyl-2-thioacylpyridinium salts 143 with sodium azide (Scheme 33). Compound 143 can be prepared from pyridium salt 142 by reaction with dithiocarboxylic acid derivatives. The synthesis can conveniently be carried out as a one-pot reaction from 2-chloro-l-pyridinium salt 142 and carbodithioate leading to final compounds 9 in high yields. The 5-alkyl-l,2,3,4-thiatriazoles 9 were isolated as oils <1990S415, 1990ZC67>. 

Thioacylation reactions with dithiocarboxylic acids are not limited to amines, but, employing the Mg salt, can also be carried out with hydroxylamine to give thiohydroxamic acids or with hydrazine and some substituted hydrazines to provide thiohydrazides. ... 

Similar reaction of dithiocarboxylic acids 75 with 2,4,6-trinitrochlorobenzene (76) in ethanol at 0°C yields thioesters 77, which are then cyclized at room temperature to the final product 78 (77JCS(P1)1273). 2-Oxo- and 2-iminocy-clopentane derivatives 79 provided compounds 80a and 80b, respectively (Scheme 13) (73JCS(P1)1009, 75JCS(P1)1277). 

In the reaction of dithiocarboxylic acids 551 with DCC the unstable dithioacetyl-sulfide 552 is formed, which undergoes dimerization to give a mixture of 1,3,5,7-tetramethyl-3,4,6,8,9,10-hexathiaadamantane 553 and cis- and rra 5-2,4-dimethyl-2. 

Dithiocarboxylic acids (118) can be converted into 1,3-dithietans (119) by acid chlorides,iodine, HCl, DCCI, or upon standing for a long time, and they are formally thioketen dimers. The cycloaddition of two C=S groups yields thioketen dimers and (120) from methyl isothiocyanate. Derivatives (121) are prepared by the reaction of dithiocarboxylic acids (118) with phosgene. ... 

Reaction with Thiocarboxylic Acids, Phosphoric Acids, Sulfonic Acids, and their Derivatives. Thiocarboxylic acids, - dithiocarboxylic acids, and dimethyldithiocarbamic acid zinc salt, as well as various phosphorus oxyacids and phosphorus thioacids, can also be utilized. a,o)-Mercapto alcohols form cyclic thioethers whereas thiols react with both DEAD and TPP-DEAD to form disulfides. 2-Mercaptoazoles also react with alcohols in the presence of DEAD and TPP. Although arenesulfonic acids do not enter into the reaction, a combination of DEAD-TPP with methyl p-toluenesulfonate as a nucleophile carrier gives the corresponding alkyl sulfonates (eq 14). Altema-... 

The degradation of CCl4 by Pseudomonas sp. strain KC involved formation of intermediate COCI2 that was trapped as a HEPES complex, and by reaction with cysteine (Lewis and Crawford 1995). Further details of the pathway that is mediated by the metabolite pyridine-dithiocarboxylic acid have been elucidated (Lewis et al. 2001). 

The degradation of tetrachloromethane by a strain of Pseudomonas sp. presents a number of exceptional features. Although was a major product from the metabolism of CCI4, a substantial part of the label was retained in nonvolatile water-soluble residues (Lewis and Crawford 1995). The nature of these was revealed by the isolation of adducts with cysteine and A,A -dimethylethylenediamine, when the intermediates that are formally equivalent to COClj and CSClj were trapped—presumably formed by reaction of the substrate with water and a thiol, respectively. Further examination of this strain classified as Pseudomonas stutzeri strain KC has illuminated novel details of the mechanism. The metabolite pyridine-2,6-dithiocarboxylic acid (Lee et al. 1999) plays a key role in the degradation. Its copper complex produces trichloromethyl and thiyl radicals, and thence the formation of CO2, CS2, and COS (Figure 7.64) (Lewis et al. 2001). 

The free dithiocarboxylic acids can be isolated, but their salts are preferred. In some cases their metal complexes can be prepared directly by insertion of carbon disulfide into metal-carbon bonds. Thus, the reaction of Grignard reagents, RMgX, with CS2, followed by acid treatment gives the dithiocarboxylic acids RCSSH and metal complexes in good yields.311... 

The reaction between [MoCl4(NCPr)2] and dithiocarboxylic acids is a general route to the preparation of eight-coordinate [Mo(S2CR)4] complexes.168 The crystal structure of [Mo(S2CPh)4] reveals these compounds to be isostructural with the dithiocarbamates, with a dodecahedral coordination around the molybdenum and average Mo—S distances of 2.475(1) and 2.543(1) A to the two different sulfur sites.170 Cyclic voltammetry has shown that in [Mo(acda)4] (Hacda = 2-aminocyclopent-l-ene-l-dithiocarboxylic acid) the Mo can be reversibly oxidized and reversibly reduced in one-electron processes.171... 

The preparation and properties of the dithiocarboxylic acids and their metal complexes have been reviewed several times.38"11 The formation of C—C bonds in the direct reaction of CS2 requires sufficiently nucleophilic carbon bases, directly or potentially accessible in the form of ambifunction-al phenoxides, organometalfic compounds, CH acidic compounds, enamines or ketimines. Carba-nions react with CS2 to give dithiocarboxylates. The preparation and purification of the adds is performed via their salts. Metal complexes are in general readily available. The bonding in these complexes is mostly of the type (27) but a bonding mode (28) is also found. Action of elemental sulfur upon heavy metal complexes of (29) aromatic dithiocarboxylic acids yields the perthio complexes (29) of these compounds. 

Dithiolanes and 1,3-dithiolenes, formation in pericyclic reactions of alkenes and acetylenes with anions of dithiocarboxylic acids 91PS(58)255. 

Another method of preparing mesoionic 1,3-dithiolones involves the reaction of dithiocar-boxylic acids with bielectrophiles. Thus treatment of aromatic dithiocarboxylic acids with a-bromoacyl chlorides in benzene in the presence of triethylamine results in the formation of the mesoionic compounds (327) (77JOC1633). 

Tellurium tetrachloride and tellurium tetrabromide reacted with four molar equivalents of dithiocarboxylic acids or their piperidinium salts. Tellurium bis[dithiocarboxylates] were formed1. However, the reaction between tellurapentathionate and dithiocarboxylates is the preferred method for the preparation of tellurium bis[dithiocarboxylates] ... 

The addition of amine to the bicyclic salt (96) initially takes place not in position 3, but in position 5, as in the reaction with mercaptans the reaction then proceeds by the same steps to yield the ester of the 1-aminocyclopent-l-ene 2-dithiocarboxylic acid (118). This ester (118) is obtained in yields of 30-65% its structure has been confirmed by independent synthesis from 119. This reaction course is again confined to the special system 118, the homologous tetramethylene-trithionium salts yielding Schiff s bases on reaction with primary amines under the same conditions.50... 

Thioesters of the type RSC(=S)R (a dithiocarboxylic ester) and RSC(C=0)R (a thiocarboxylic ester) can be generated by reaction of carboxylic acids with thiols. 

Tellurium tetrachloride and tellurium tetrabromide were converted to tellurium dithiocarboxylate halides in reactions with two or fewer molar equivalents of dithiocarboxylic acids or their piperidinium salts Reactions with a 3 1 molar ratio of the reagents (dithiocarboxylate/tellurium tetrahalide) were not carried out. 

These reactions were also carried out in dichloromethane at 0 with the piperidinium dithiocarboxylates instead of the dithiocarboxylic acids. ... 

Contrary to carboxylic acids which, under normal conditions, only give salts with amines, dithiocarboxylic acids, RCS2H, are quite reactive in nucleophilic displacement reactions. However, the compounds are unpleasant to handle and, due to their limited stability, often give only low yields of thioamides in the reaction with amines.The approach was successfully employed in the synthesis of thiobenzoyl azolides, e. g. in the formation of (7) according to equation (4). °... 

The reaction of CH acidic compounds with CS2 in the presence of excess base yields dianions of dithiocarboxylic acids. Starting from camphor, neutralization with HCl and addition of primary amines yields 3-oxonorbomanethiocarboxamides (11) with undefined stereochemistry (Scheme 3). ... 

Thioacyl chlorides, RCSCl, are powerful thioacylating agents as is obvious from the quantitative thiobenzoylation of the only moderately nucleophilic nitrogen in thiocarbamate (13 equation 5). However, severe limitations are the difficult accessibility of thioacyl chlorides and their thermal lability. Even if they are prepared from dithiocarboxylic acids using an improved procedure, only thioaroyl chlorides, particularly PhCSCl (12), can be handled sufficiently easily to be used in synthetic work. Thus, various azoles react with (12) to furnish /V-thiobenzoyl azolides (14) in the presence of excess azole or NEts (equation 6) a particularly clean and fast reaction is achieved if IV-silylated azoles are employed. However, considering the fact that the chloride has to be prepared from the dithiocarboxylic acid, the approach of equation (4) presents a shortcut to the products. 

Thiols can also be thioacylated, in the same way as alcohols (Section 2.5.3.2), by reaction with bis-thioacyl thioanhydrides (equation 58). The preparation of aromatic as well as aliphatic thioanhydrides is possible according to novel procedures described by Kato et a/., e.g. from the corresponding dithiocarboxylic acids and DCC or 2-chloro-N-methylpyridinium iodide.Even sterically hindered di-thioesters are obtained (equation 58). ... 

Iodotriethyl(nthotrithiobenzoate, a readily accessible compound, on reaction with methanol loses ethanethiol to give the methylorthobenzoate (421 equation 198). Dialkoxydibutylstannanes convert dithiocarboxylic acid esters to oithoesters (422 equation 199). From orthoesters and chloral the orthoesters (423 equation 200) can be synthesized. "... 

Both cis and rrafw-3-phenoxycinnamic acids cyclize with phosphorus pentoxide to pyran>4-ones but the corresponding phenylthiocinnamic acid isomers behave differently the traits isomer gives a thiopyranone whereas the cis compound produces an indenone. Diels-Alder reactions with heterodienes have been reviewed [24SS, 3067a, 3880]. Indole-3-dithiocarboxylate esters act as dienes in the Diels-Alder reaction with DMAD (cf. Chapter 65, Section II.7). 

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