Dithiocarbamic acid salts, from amines

Salts of dithiocarbamic acid can be prepared by the addition of primary or secondary amines to carbon disulfide. This reaction is similar to 16-9. Hydrogen sulfide can be eliminated from the product, directly or indirectly, to give isothiocyanates (RNCS). Isothiocyanates can be obtained directly by the reaction of primary amines and CS2 in pyridine in the presence of DCC. ° In the presence of diphenyl phosphite and pyridine, primary amines add to CO2 and to CS2 to give, respectively, symmetrically substituted ureas and thioureas ... 

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... 

Synthesis of Dithiocarbamates from CSj. The addition of ammonia or alkylamines to CS2 to form the amine salts of dithiocarbamic acids is analogous to their addition to CO2 to form the corresponding carbamate salts. 

Salts of dithiocarbamic acids from amines NH NCSS ... 

The conversion of the weakly UV-absorbing primary and secondary amines to the more strongly absorbing dithiocarbamic acids has been used to reveal the firee amines on thin-layer plates [47]. The plates were sprayed with dilute ammonia to free the bases from their salts before exposure to carbon disulfide. 

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). 

All secondary amines react with carbon disulfide in ammoniacal solution with the formation of ammonium salts of dithiocarbamic acids, which do not decompose in the presence of metal salts (in contrast to similar compounds derived from primary amines), but give, for example, an insoluble salt with a nickel salt (16) ... 

Jones et al. (67) also prepared a wide range of water soluble ammonium dithiocarbamate salts, [NH4][S2CNR2] (Fig. 5). They result from the iifitial reaction of the amine with concentrated aqueous ammonia in ethanol, followed by later addition of carbon disulfide at low temperatures. For example, diethanolamine, HN(CH2CH20H)2, forms a yellow precipitate in 65% yield. Castro et al. (68) studied the kinetics and mechanism of the reactions of piperidine, pyrrolidine, morpholine, and benzylamine (69) with carbon disulfide in ethanol (Fig. 6). They proceed via a dithiocarbamic acid intermediate (4), which in turn yields the dithiocarbamate anion (5) upon proton loss to the amine. While for pyrrolidine, formation of the dithiocarbamic acid is rate determining and proceeds to the dithiocarbamate irreversibly, for both morpholine and benzylamine, the transformation is reversible. Further, in these cases the ethoxide anion is found to catalyze the transformations. They have also determined that pyrrolidine is 200 times more nucleophilic toward carbon disulfide than piperidine, despite the later being only slightly more basic, a feature that may relate to the irreversible nature of the formation of pyrrolidine dithiocarbamate. 

Absorphon of CO2 in aqueous solutions of MEA absorption of H2S and mercaptans in aqueous soluhons of alkanolatnines and caushc soda absorption of carbon monoxide in aqueous cuprous ammonium chloride solutions absorphon of lower olefins in aqueous soluhons of cuprous ammonium compounds absorption of pure chlorine in aqueous solutions of sodium carbonate or sodium hydroxide conversion of dithiocarbamates to thiuram disulfides sulfonation of aromatic compounds with lean SO3 recovery of bromine from lean aqueous solutions of bromides reactions of importance in pyrometallurgy absorphon of CO2 in aqueous solutions of caustic alkahes and amine absorption of O2 in aqueous solutions of sodium dithionite absorphon of O2 in aqueous sodium sulfite soluhons absorption of O2 in alkaline solutions containing the sodium salt of 1,4-napthaquinone- 2-sulfonic acid (NQSA) special case role of diffusion in the absorption of gases in blood in the human body. 

Diarylamines do not react with carbon disulfide, whereas dialkyl amines readily form dithiocarbamates. However, NjAT-diaryldithiocarbamates can be prepared from metal salts of diarylamines and carbon disulfide (15). They are more stable than dialkyldithiocarbamic acids, eg, N,N -diphenyldithiocarbamic acid [7283-79-6], mp 142°C. Similarly, various metal salts of DPA react with carbon dioxide and an epoxide to give the P-hydroxyalkyldiphenylcarbamates (16). 

Thiadiazines 238a and 238b are prepared from primary amines and carbon disulfide under basic conditions. The potassium dithiocarbamate salts 239 formed react with 2equiv of formaldehyde and the corresponding primary amine/amino acid to furnish the desired thiadiazines 238 (Scheme 45) <1999JME5359>. 

In addition to water,many ligands (such as ammonia,amines,amino acids,A salts of CN, ambidentate NCS, the halides X, dithiocarbamates R2NCS2 ) are today readily purchased or prepared from chemicals which were uncommon in 1900.This option has a strong impact on which part of a species studied are considered as ligands. However,one can,in a few minutes,produce a long series of paradoxes. Is it suitably that F CCH is a complex of the carbanion CF with is Te(CH ) a coitplex... 

They are easily prepared from dithiocarbamate and nickel(ll) salts, and examples including those derived from simple amines (587,1472) fluorinated amines (76) amines with (O-hydroxyl groups (1473) indole (341) indoline, carbazole, and imidazole (342) (72) together with those with heterocyclic (72,1116,1126,1424,1474) benzyl (346,1475) and aryl (95,1423,1425,1476, 1477) substituents. Others include examples prepared from Schiff bases (1121), 2-aryldecahydroquinolin-4-ones (1478), tetrahydroquinoline and tetrahydroiso-quinoline (1479), succinimide and phthalimide (49), l,4,7,10-tetraoxa-13-aza-cyclopetadecane (50), 1,3,4-thiazolyl (1426), and 3-dithiocarboxy-3-aza-5-aminopentanoate (343) (1480,1481). A wide range of amino acid derivatives have also been prepared (122,133-137), as have derivatives of glycine, DL-alanine and DL-valine peptide bonded to ethyl esters of a-amino acids (134). 

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