Carbon disulfide, dithiocarbamate synthesis copper

These are easily prepared by the reaction of amines with carbon disulfide (1) in the presence of alkali (Scheme 17).2 The synthesis of dithiocarba mates (4) was first reported by Debus in 1850. Dithiocarba mates (4) form metal chelates, and sodium dimethyl dithiocarbamate is used in quantitative inorganic analysis for the estimation of metals, e.g. copper and zinc. Dithiocarba mates are also employed as vulcanisation accelerators and antioxidants in the rubber industry, and as agricultural fungicides.3 The parent dithiocarbamic acids are unstable, decomposing to thiocyanic acid and hydrogen sulfide however, the salts and esters are stable compounds. Dithiocarba mates (4) are oxidised by mild oxidants to the thiuram disulfides (38) (Scheme 17). 

Cadmium decreases testosterone production by preventing the synthesis of cholesterol, a precursor of all steroid hormones. Other chemicals that interfere with steroid hormone synthesis include aminoglute-thimide, cyanoketone, and ketoconazole. Copper chelating compounds, such as dithiocarbamates, metam sodium, and carbon disulfide, suppress the conversion of dopamine to norepinephrine and subsequently to epinephrine. 

Thiram and other dithiocarbamates are metabolic poisons. The acute effects of thiram are very similar to that of carbon disulfide, supporting the notion that the common metabolite of this compound is responsible for its toxic effects. The exact mechanism of toxicity is still unclear, however it has been postulated that the intracellular action of thiram involves metabolites of carbon disulfide, causing microsome injury and cytochrome P450 disruption, leading to increased heme-oxygenase activity. The intracellular mechanism of toxicity of thiram may include inhibition of monoamine oxidase, altered vitamin Bg and tryptophan metabolism, and cellular deprivation of zinc and copper. It induces accumulation of acetaldehyde in the bloodstream following ethanol or paraldehyde treatment. Thiram inhibits the in vitro conversion of dopamine to noradrenalin in cardiac and adrenal medulla cell preparations. It depresses some hepatic microsomal demethylation reactions, microsomal cytochrome P450 content and the synthesis of phospholipids. Thiram has also been shown to have moderate inhibitory action on decarboxylases and, in fish, on muscle acetylcholinesterases. 

CS2 as a type of liquid sulfur source was applied in benzothiazole synthesis as well. In 2011, Ma and co-workers found that copper salt can catalyse the reaction between 2-haloanilines and dithiocarbamate, which was generated in situ from amines and carbon disulfide (Scheme 2.145a). ° 2-N-Substi-tuted benzothiazoles were produced in good yields. Later on, they found that thiols can be applied as well. Condensation of carbon disulfide with thiols in... 

Recently, Ma et al. developed a three-component reaction for the synthesis of 2-A -substituted benzothiazoles 107 via the copper-catalyzed coupling of 2-iodoanilines, carbon disulfide, and secondary amines (Scheme 3.56) [149]. In these reactions, the condensation of CS with an amine in the presence of a base generates dithiocarbamate salts XXXV, which undergo coupling with 2-iodoanilines to give XXXVI and subsequent intramolecular condensation and elimination to afford the substituted benzothiazoles 107. 

It is not clear when dithiocarbamates were first prepared, but certainly they have been known for at least 150 years, since as early as 1850 Debus reported the synthesis of dithiocarbamic acids (1). The first synthesis of a transition metal dithiocarbamate complex is also unclear, however, in a seminal paper in 1907, Delepine (2) reported on the synthesis of a range of aliphatic dithiocarbamates and also the salts of di-iTo-butyldithiocarbamate with transition metals including chromium, molybdenum, iron, manganese, cobalt, nickel, copper, zinc, platinum, cadmium, mercury, silver, and gold. He also noted that while dithiocarbamate salts of the alkali and alkali earth elements were water soluble, those of the transition metals and also the p-block metals and lanthanides were precipitated from water, to give salts soluble in ether and chloroform, and even in some cases, in benzene and carbon disulfide. 

Ma et al. developed a copper-catalyzed cascade condensation/S-arylation/hetero-cyclization for the three-component synthesis of 2-iV-substituted benzothiazoles 113 from amines, carbon disulfide, and 2-haloanilines (Scheme 5.75) [78]. The first step in this process is the reaction between amine and carbon disulfide in the presence of bases to form dithiocarbamate salt A. Then, the in situ-generated A undergoes... 

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