Carbon Disulphide amino acids with

Japanese workers have developed a new synthesis of ureas and thioureas through the reaction of carbon dioxide or carbon disulphide with diphenyl phosphite and primary amines. The reaction is thought to take place via an intermediate (85), followed by elimination to give isocyanate or direct displacement by amine. The principles of this new synthesis have also been applied to the preparation of peptides and amino-acid esters. 

Anthoni and his co-workers, in a comprehensive paper, have described the syntheses of several dithiocarbazic acids by the reaction of differently substituted hydrazines with carbon disulphide. The reaction of 2-amino-ethylhydrazine with carbon disulphide has been reported to give the inner salt (315), which, however, easily rearranges to (316). In addition, the reactions of carbon disulphide with isothioureas, which probably involve... 

The most important condensation reactions used for analytical purposes in organic polarography are reactions of carbonyl compounds with the formation of (1) aldimines and ketimines, (2) semicarbazones, (3) hydrazones and (4) oximes. The reactions of carbon disulphide with amines and amino acids are also used (5). 

Crystalline solid m.p. 35-36 "C, b.p. 154--156 C, prepared by oxidizing A,A -dicycIo-hexylthiourea with HgO in carbon disulphide solution, also obtained from cyclohexylamine and phosgene at elevated temperatures. Used as a mild dehydrating agent, especially in the synthesis of p>eptides from amino-acids. Potent skin irritant. 

Several examples exist for the conversion of 5-aminothiazoles into the corresponding thiazolopyrimidines. Shaw and Butler report the formation of aminothiazole thiocarboxyamide 27 from the thioamide 26 and carbon disulphide using Cook and Heilbron s procedure. Methylation of 27 gave carboxythioimidate 28 which then reacted with sodium hydroxide to give amino-nitrile 29, and with formic acid and acetic anhydride to give the thiazolopyrimidine 30. 

N-Thiocarbonyl alkyl esters of amino acids were chromatographed by Halpern et al. [286]. Their preparation proceeds according to Scheme 5.29. The reaction sequence includes esterification of amino acids followed by reaction with carbon disulphide and triethylamine, giving rise to dithiocarbamate. Reaction of the latter with chloroformate... 

Treatment of thionhydrazides, RC(==S)—NH—NH2 with nitrous acid should lead to thiocarbonyl azides, RC(=S)—N3, and it seems likely that these azides are indeed formed as short-lived intermediates. The isolated products are 1,2,3,4-thiatriazoles. When thiosemi-carbazides are nitrosated, 5-amino-l,2,3,4-thiatriazoles or/and 5-mercaptotetrazoles are obtained. Freundformulated his products as such in 1895, while Oliveri-Mandala considered them thiocarbamoyl azides on the basis of some chemical evidence. Lieber resolved this controversy by recording the infrared spectra of the compounds and demonstrating the absence of an azide band . He did the same for the 5-alkylmercapto-l,2,3,4-thiatriazoles , which had earlier been reported as azido-dithiocarbonates , and for the products from azide ion and thiophosgene and carbon disulphide , all of which possess thiatriazole structures. Lieber also demon-... 

Figure 1.24 Depiction of disulphide bridges from Lysozyme (hen egg-white) (pdb 6lyz). (a) Ribbon Display Structure (see Section 1.2.5 each flat helical ribbon is an a-helix each flat strand is /3-strand thin strands are loops and turns) of lysozyme (side view), atoms and bonds of amino acid side chains of cysteine residues involved in disulphide bridges are rendered in ball and stick representation with sulphur (yellow) carbon (grey), nitrogen (blue) and oxygen (red) (b) ball and stick representation of cysteine residues forming a right-handed disulphide bridge, atoms and bonds labelled as for (a) (c) ball and stick representation of cysteine residues from a left-handed disulphide bridge, atoms and bonds labelled as for (a).

Reactions of carbon disulphide. In alkaline solutions carbon disulphide reacts with amines to form dithiocarbamino-carbonic acid. This reaction was used for the determination of amino acids and carbon disulphide. 

Several examples of the applications of polarography in these fields have been already mentioned in Chapters VI and VII, viz. determinations of benzene, toluene, naphthalene and phenols in the atmosphere, breath, blood or urine, of amino acids (with particular interest to tyrosine, tryptophane, phenylalanine, histidine and histamine), of ketoacids, ketosteroids, carbon disulphide in air and blood, ethanol, acetoin, sugars and morphine in blood, of lactic acid, mandelic acid in bile and urine, adrenaline and thyroxine in iodinated proteins and last, but not least, of thiol compounds, both soluble and bound in biological materials. A few further examples will be given here. 

The A -heteroarylthiourea derivative (89) was obtained from the corresponding 2-dec -2-isothiocyanato-derivative, and its tautomeric equilibrium in solution was studied by i.r. and H-n.m.r. spectroscopy. Condensation of 2-chloroethylamine with the 2-deoxy-2-isothiocyanato derivative gave either the thiazoline (90) or the thiourea (91) depending upon the solvent. Related thiourea-linked disaccharides are discussed in Chapter 10. Reaction of the acetic acid salt of 1-amino-1-deoxy-D-fructose with carbon disulphide at 75°C gave the spirocyclic derivative (92) in 49% yield. ... 

Dihydrothiophens are readily available by Birch reduction of thiophens, and they may be alkylated adjacent to activating substituents. Subsequent removal of sulphur provides a useful route to substituted butadienes. Finally in this Section the preparation of l,2-dithiolo[3,4-with carbon disulphide in the presence of sodium hydroxide and dimethyl sulphate gives good yields of the expected pyrimido[4,5-6]quinolines (210). However, upon acid work-up in the absence of Me2S04 the reaction follows a different course. The amino-function is lost and the sulphur heterocycles (209) are obtained. 

Amino-2-thiocyanatocyclohex-2-enone, on treatment with acid, gave the dithiin (27). Derivatives of acyclic ketones yielded different products. The dithiin 1,1-dioxide (28) has been prepared by treatment of the anion of dibenzyl sulphone with two equivalents of carbon disulphide followed by methylation. 

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