Dithiocarbamic acid esters amines

Dithiocarbamic acid esters from amines NH -> NGSSR... 

Dithiocarbamic acid itself and its alkali metal salts are unstable towards hydrolysis but metal chelates are known and a structure of [Co(S,CNH2)3] is available (Table 96). This complex is probably unstable towards hydrolysis giving [Co(S2CO)3]3. Salts of dithiocarbamates derived from primary amines are also unstable under alkaline conditions, although N(3)-substituted dithiocar-bazic acid forms green tris(S,S) chelates (336).1133 The similar N(3)-unsubstituted acids form (N,S) chelates (337) which can be deprotonated when R = H with possible isomerization to the (S,S) dithiocarbimate chelate (339).1133 The (N,S) chelate (338) has been positively identified by a crystal structure of its 5-methyl ester, R = H (Table 96).1134... 

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). 

Method A Dithiocarbamic acid and a-halo carboxylic acid (ester). B Amines and bis-(carboxymethyl) trithiocarbonate. 

In lubricating compositions, these compounds show excellent antioxidant synergy with aromatic amines such as alkylated diphenylamines [43] and sulphur compounds such as metal dihydrocarbyl dithiophosphate, a metal dithiocarbamate, sulphurised olefins, alkyl and aryl sulphides, alkyl and aryl polysulphides, sulphurised carboxylic acid esters, sulphurised alkylphenols, reaction product of an olefin and sulphurised alkylphenol, and phosphosulphurised terpenes or mixtures thereof [43],... 

Aromatic amines are too weak to undergo the above reactions they do add to carbon disulfide but the resulting dithiocarbamic acids cannot form salts the resulting unstable free acids decompose at once with evolution of hydrogen sulfide and formation of isothiocyanates which add the excess of amine and thus give thioureas as final products 93,94 a small amount of sulfur catalyses the formation of the thioureas.95 Treatment of salts of the dithiocarbamic acids obtained in this way with chloroformic esters in chloroform at 0° leads to loss of COS and alcohol and formation of isothiocyanates in high yield.96... 

Carbamates comprise the esters and the salts of carbamic acids. This is a systematic classification from chemical aspects. Microbicides of this class of substances widely differ in terms of both efficacy and mechanisms of activity. The carbamic and dithiocarbamic acids, the basis of the carbamates, lack chemical stability they occur only intermediarily and disintegrate instantly to form carbon dioxide (CO2), carbon disulphide (CS2) and amine (see Fig. 31). 

Dithiocarbamic acid vinyl esters from amines NH N... 

Dithiocarbamic acid vinyl esters from amines 638. (n-G3H7>2NH + GSg + HG = GH ->... 

Four main types of antioxidants are commonly used in polypropylene stabilizer systems although many other types of chemical compounds have been suggested. These types include hindered phenolics, thiodi-propionate esters, aryl phosphites, and ultraviolet absorbers such as the hydroxybenzophenones and benzotriazoles. Other chemicals which have been reported include aromatic amines such as p-phenylenediamine, hydrocarbon borates, aminophenols, Zn and other metal dithiocarbamates, thiophosphates, and thiophosphites, mercaptals, chromium salt complexes, tin-sulfur compounds, triazoles, silicone polymers, carbon black, nickel phenolates, thiurams, oxamides, metal stearates, Cu, Zn, Cd, and Pb salts of benzimidazoles, succinic acid anhydride, and others. The polymeric phenolic phosphites described here are another type. 

Thus, 1-aminothiohydantoins (223) can be made in good yields by reaction of ethyl 2-hydra-zinoacetate with a suitable alkyl thiocyanate <92MI 302-02). Similarly, an a-amino acid, heated with a dithiocarbamic ester, gives a thiohydantoin. An adaptation of this is a one-pot procedure from amino acid, amine, carbon disulfide and base without isolating the dithiocarbamic ester (Scheme 156) <835391 >. 

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