Carbonates thiocarbonates

T. L. Huang, A. Szekacs, T. Uematsu, E. Kuwano, A. Parkinson, B. D. Hammock, Hydrolysis of Carbonates, Thiocarbonates, Carbamates, and Carboxylic Esters of a-Naph-thol, /LNaphthol, and p-Nitrophenol by Human, Rat, and Mouse Liver Carboxylesterases , Pharm. Res. 1993, 10, 639 - 648. 

The substituted ferrocenes 757 are widely used as metal-ligand systems. These compounds have a great variety of chelating groups (R) (1-diketones (a) [458], semicarbazones and thiosemicarbazones (b) [458], azomethines and their analogues (c) [458-462], oximes (d), carbonic, thiocarbonic (e), and amino acids (f) [458] ... 

Iron and Carbon-Iron Carbides—Cementite—Iron Carbonyls—Ferrous Carbonate-Complex Iron Carbonates—Thiocarbonates. 

Carbonates, Thiocarbonates, and Related Anions, The syntheses of carbonates, hydroxide carbonates, and oxide carbonates have been reported. Those factors which influence the crystallization of rare-earth carbonates have been investigated the carbonates were precipitated at various temperatures from aqueous solutions by using sodium carbonate (20—80 C), sodium bicarbonate (20—80 °C), trichloroacetic acid (40—120 °C), and urea (50—150 °C) as precipitants. The carbonates so formed were characterized by chemical analysis and A"-ray powder diffraction techniques. It was found that they could be classified into several phases (Table 19) according to the ionic radii... 

Carbonyl sulfide reacts slowly with aqueous alkah metal hydroxides, which can therefore be used to free carbonyl sulfide from acidic gases. The half-hfe at pH 12 (0.01 N KOH) is 3 min at 22°C. The product initially formed from carbonyl sulfide and aLkaU is the thiocarbonate [534-18-9] which then breaks down to carbonate and sulfide ... 

A number of less-hazardous reagents that can be substituted for tert-hutyl azidoformate in tert-butoxycarbonylation reactions are available including 2-(te/t-butoxycarbonyloxyimino)-2-phenylacetonitrile (Aldrich Chemical Company), 0-teri-hutyl N-phenyl thiocarbonate (Eastman Organic Chemicals), di-butyl dicarbonate and tert-butyl phenyl carbonate. ... 

Kohlen-schwarz, n. carbon black charcoal black, -schwefelwasserstoffsaure, /, (tri)-thiocarbonic acid (H2CS1). -spat, m. anthraconite whewellite, -spitze,/. carbon point, -staub, m. coal dust charcoal dust, -stick-stoff, m. cyanogen, -stickstoffsaure, /, car-bazotic acid (picric acid), -stoff, m. carbon,... 

Alcohols can readily be converted to carbonate and thiocarbonate derivatives. Under... 

A 1,3-oxathiolane derivative (100) is formed when 2-mercaptoethanol is carbonylated by nickel carbonyl in pyridine (Scheme 118).181 It is probable that the mechanism involves carbonyl insertion into the Ni—S bond of intermediate thiolatonickel complexes and it is significant that compounds in this category (cf. 101,102) can be transformed into the cyclic thiocarbonate by treatment with carbon monoxide (Scheme 118).181... 

Interesting findings have been reported for the hydrolysis of a- and fi-naphthyl thiocarbonates (7.67, R = Me or Et) by mammalian liver carboxylesterases [43]. In comparison with their carbonate analogues (7.21), the thiocarbonates were more lipophilic by one log P unit and were hydrolyzed at rates modestly to markedly slower. These two findings are apparently unrelated. 

Heating cyclic mono-, di- or tri-thiocarbonates, usually in the presence of base, gives thiiranes and carbon dioxide, carbon oxysulfide or carbon disulfide respectively. The methiodide salts of 2-methylimino-l,3-oxathiolanes are converted to thiiranes with high stereoselectivity, except for 5-aryl-substituted oxathiolanes (Scheme 146) (80LA1779). Flash vacuum thermolysis of l,3-oxathiolan-5-ones causes loss of carbon dioxide and nearly quantitative formation of thiiranes of inverted configuration (Scheme 147) (80JA744). For example, thermolysis of c/s-2,4-diphenyl-1,3-oxathiolan-5-one gives trans-2,4-diphenyl-thiirane. 

The dipole moments of three asymmetric polythiocarbonates derived from bisphenol A are determined in benzene solution at 298 K. Good agreement between theoretical and experimental results can be obtained assuming that the direction of the dipole moment of the thiocarbonate group Is opposite to that in carbonate residues. 

Carbon disulphide interacts with dry ammonia, but the reaction has not yet been fully investigated the gas is slowly absorbed and a dark brown liquid results, which probably contains ammonium thiocarbonate and thiocyanate.6 An alcohol solution of ammonia readily dissolves carbon disulphide,7 the foregoing products being formed (see also p. 264).8... 

Carbon disulphide, like the dioxide, is the anhydride (or, more strictly, thioanhydride) of a feeble acid, thiocarbonic acid, H2CS3. Moreover, between carbonic and thiocarbonic acids a number of intermediate acids are capable of existence. They are as follows ... 

Calcium and sodium carbonates react with the acid forming the corresponding thiocarbonates, thus ... 

Ammonium thiocarbonate, (NH4)2CS3, may be prepared by digesting ammonium pentasulphide with carbon disulphide under a reflux condenser a white deposit of ammonium monosulphide first forms on the condensing surface and is gradually converted into the thiocarbonate, becoming pale oiange-coloured. On exposure to moist air it turns red. 

It was generally supposed that the removal of carbon disulphide from crude coal gas when purified by lime was due to its absorption by calcium sulphide with the formation of calcium thiocarbonate, but Yeoman2 suggests that it is the perthiocarbonate, CaCS4, which is formed. This suggestion accounts for the necessity of the presence of some oxygen in order that absorption may take place. 

The thiocarbonates of the alkali and alkaline earth metals are soluble in water. The alkali thiocarbonates are yellow in colour. In concentrated solution these salts are fairly stable, but in dilute solution they are gradually decomposed, forming the carbonate and hydrogen sulphide. 

Thiocarbonates, especially the alkali thiocarbonates, are used in agriculture to prevent certain diseases, notably phylloxera of the vine. It is carbon disulphide which is the active material of these fungicides.3... 

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