Potassium thiocarbamate

Keywords potassium thiocarbamate, ethyl bromoacetate, basic alumina, micro-wave irradiation, thiadiazolyl thiazolothione... 

Basic alumina (18 g) was added to the solution of ethyl bromoacetate 2 (0.01 mol) in dichloromethane (20 mL) and to the solution of potassium thiocarbamate 1 (0.01 mol) in hot acetone (5 mL) at room temperature in two separate beakers. Adsorbed material was dried and the two reactants mixed properly using a mortar and pestle. The reaction mixture was kept inside an alumina bath and irradiated in a microwave oven for 100-110 s. The mixture was cooled and the product was extracted into CH2C12 (5x4 mL). The product was collected by evaporating the solvent and recrystallizing from a mixture of methanol and CH2C12. 

Uses. There may be some captive use of carbonyl sulfide for production of certain thiocarbamate herbicides (qv). One patent (38) describes the reaction of diethylamine with carbonyl sulfide to form a thiocarbamate salt which is then alkylated with 4-chloroben2yl haUde to produce 3 -(4-chloroben2yl) A[,A/-diethylthiocarbamate [28249-77-6] ie, benthiocarb [28249-77-6]. Carbonyl sulfide is also reported to be useful for the preparation of abphatic polyureas. In these preparations, potassium thiocyanate and sulfuric acid are used to first generate carbonyl sulfide, COS, which then reacts with a diamine ... 

The reaction of sucrose 2,3-manno-epoxide with potassium thioacetate and ammonium chloride in aqueous ethanol gave the expected 3-5>-acetyl-3-thio-altropyranoside (101). Treatment of 6,6,-dibromo-6,6,-dideoxysucrose hexaacetate with potassium thioacetate and A/, Ak dimethyl thiocarbamate gave the corresponding derivatives of 6,6,-dithiosucrose. The air oxidation of 6,6,-dithiolsucrose gave the bridged 6,6,-episulfide. A detailed conformational study of sucrose 6,6,-dithiol and sucrose 6,6 -episulfide revealed that they are similar but distinguishable (102). 

Tellurium tetrakis[bis(2-hydroxyethyl)dithiocarbamate] was treated with an aqueous solution of potassium iodide. Black crystals of tellurium bis[bis(2-hydroxyethyl)di-thiocarbamate diiodide were obtained4. 

Coupling of a benzoic acid derivative under basic conditions is achieved with alkyl iodides," alkyl chlorides,dimethyl sulfate, or (l,1-dihydroperfluoroalkyl)phenyliodonium triflates. Common bases used arc potassium carbonate or sodium hydroxide (with phase-transfer catalyst). " Again, employing acid chlorides " - or anhydrides, " is the method of choice. The reaction can be performed without further activation, " " but in most cases the transformation takes place in the presence of the usual bases, triethylamine - " or pyridine " " " " " [in some cases 4-(dimethylamino)pyridine is added " ]. In a similar manner carbamates. thiocarbamates, " or thiocarbonates are synthesized. Perfluoropropcn-2-ol... 

This reaction was carried out on cyclic and acyclic allylic carbonates. The 5-allylic thiocarbamate products were hydrolyzed to the corresponding thiol or reacted with 2-chloropyrimidine in the presence of potassium hydroxide to provide the sulfide without any loss in stereochemical purity for either example. a-Acetoxysulfones can be regarded as acid-stable, but base-labile, chiral aldehyde equivalents. These can be accessed through the palladium(0)-cataly zed reaction of geminal esters with sodium benzenesulfinate under phase-transfer conditions (eq 12). ... 

The reaction mixture is made alkaline with 50 ml. of 10% potassium hydroxide solution and is shaken three times with 100-ml. portions of benzene. The organic layers are combined, washed with a saturated sodium chloride solution, and dried by filtration through anhydrous magnesium sulfate. The solvent is removed by distillation to give the crude product that is crystallized from 75 ml. of absolute methanol to yield 23.5-25.2 g. (68-73%) of colorless crystals of 0-2-naphthyldimethyl-thiocarbamate, m.p. 90-90.5°. 

Perhydro-3,l-benzoxazine-2-thiones (83) cis and trans) react with methyl iodide and potassium hydroxide to afford 2-methylthio derivatives (84), but in the absence of potassium hydroxide ring opening occurs to produce iodomethyl thiocarbamates (85) (Scheme 18). In the latter case it is assumed that hydrogen iodide released in the first S-methylation step is responsible for initiating... 

Xanthic acid was investigated by Couerbe. Zeise discovered thiocarbamic acid by the action of carbon disulphide on ammonia, the addition compound of ethylene and platinous chloride (Gekohltenwasserstoffes Chlorplatin), and mercaptan (from corpus mercurium captans), by distilling potassium hydrosulphide with potassium ethyl sulphate KKS +0211 0—... 

Oxathians the formation of cyclic trithio-orthocarbonates (193) by the thermolysis of bis-(dithiocarbonates) the preparation of l,3-oxathiol-2-ones and of 2-substituted 1,3-oxathioles by treatment of moKlibromo-ketones with potassium ethyl xanthate a novel synthesis of 2/f-l,3-benzoxathiol-2-ones (194) by the HI- or pyridine-hydrochloride-induced cyclization of thiocarbamates and the base-catalysed cyclization and Smiles rearrangement of 3-(2,4,6-trinitrophenyl-thio)propanoI to give the benzoxathiepin (195). ... 

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