Dimethyl thiocarbamate

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). 

The deoxygenation reaction by similar single electron transfer process is also useful for the reduction of mesylates, while tosylates regenerate by hydrolysis the alcohol [86, 87] in the presence of base without epimerization. High yields are obtained in general, while in alcoholic solution, vV,/V-dimethyl thiocarbamates lead to reduction products in low yields with a predominant deprotection process [88] (Scheme 45). 

The MNK rearrangement proceeded smoothly to furnish S-aryl dimethyl-thiocarbamate. A temperature of 280 °C was necessary for clean conversion. Eventual hydrolysis with sodium hydroxide and acidification with dilute acid chloride promoted the cyclisation to thiocoumarin 83. 

The reaction of the formally dipole-stabilized carboanions with a variety of electrophiles gives 2,3-substituted thiiranes (Scheme 74). Ethyl jV,7V-dimethylthiocarbamate (209) undergoes lithiation to give (210), which readily reacts with benzaldehyde to give the thiirane (212) in 81% yield by way of the i -hydroxy adduct (211). The synthesis of thiirane (214) from n-pentyl-jV,jV-dimethyl-thiocarbamate (213) is shown in Equation (33) <82JOC3855>. 

Methyl Selenac . [R.T. Vanderbilt] Selenium dimethyl thiocarbamate vulcanizing agent, accelerator for rubbo. ... 

DiaminO 4,4-dimethyl-l,3,5-thiadiazine hydrobromide was isolated as by-product (418). Benzene sulfonates of cyanohydrin prepared from sodium cyanide and an halobenzoaldehyde, when treated with thiourea or its derivatives, afford 2,4-diamino-5-(p-halogenophenyl)-thiazole benzene sulfonates (447). Similarly, cyanoamido thiocarbamates obtained from cyanamide and isothiocyanates yield substituted 2,4-diaminothiazoles (598). 

As the key precursor towards the realization of 1,7-epoxy cyclononanes and 1,8-epoxycyclodecanes, an 1 l-oxatricyclo[6.2.1.02,6]decane skeleton was constructed by using the Hoffmann [4+3] cycloaddition methodology <07EJO4383>. In Majetich s total synthesis of (-)-salviasperanol, the key step was the trifluoroacetic acid-promoted isomerization of a vinyl epoxide to 2,5-dihydrofuran, whose O-thiocarbamate was removed by radical reaction to produce salviasperanol dimethyl ether <07OL85>. The synthetic route is depicted below. 

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... 

DIHYDRO-2,2-DIMETHYL-7-BENZO-FURANYLMETHYL(1,1,2,2-TETRA-CHLOROETHYL)THIOCARBAMATE... 

The corresponding reactions of 3-alkoxy-5-aryl-5,6-dihydro-1,4,2-dithiazine 1,1-dioxides with aqueous alkali give O-alkyl (styrylsulfonyl)thiocarbamates 2 9 similarly, the sodium salts of 5-aryl-l, 4,2-dithiazine-3-thiol 1,1 -dioxides in the presence of dimethyl sulfate give 5,5-dimethyl JV-(styrylsulfonyl)dithiocarbonimidates, e.g. 3."... 

Dazomet, Tetrahydro-.t.5-dimelhyl-2l -l, .1.5-thia-diazine-2-thione 2 -thio -3,5 -dimethyltetrahydro -1,3,5 -thia -diazine 3,5 -dimethyl -2 -i hionoietrahydro -1,3,5 -thiadiazine dimethylformocarbothialdine DMTT, Crag 974 Mylone. CjHjoNjS, mol wt 162.27. C 37.01%, H 6.21%, N 17.27%, S 39.52%. Frepd by the action of carbon disulfide on trimeth-yltrimethylenelriimine Dalepine, Bull. Soc. Ckim. 15, 891 (1897) from formaldehyde and methylammonium methyldi-thiocarbamate Bodendorf. J. Prakl. Chem. 126, 233 (1930) Ainley et al. J. Chem. Soc. 1944, 147. Prepd commercially by the reaction of carbon disulfide, meihylamine and caustic soda Chem. Week 79, no. 18, 82-83 (1956). 

Thioureas are obtained analogously by boiling an amine hydrochloride and an alkali thiocyanate in aqueous solution66 or an amine and a thioiso-cyanate in alcohol 67 aromatic thioisocyanates generally react even in the cold. Further, aqueous ammonia solutions are converted smoothly into mono-alkylthioureas by isothiocyanates.68 Isothiocyanates can be converted directly into symmetrical thioureas by boiling them in aqueous dimethylformamide or dimethyl sulfoxide the thiocarbamic acids formed as intermediates by partial hydrolysis add to unchanged isothiocyanate with loss of COS.69... 

Dimethyl sulphoxide Naphthas Special solvents Carbamate, thiocarbamate Steam-cracked Cg - C7 aromatics... 

Rundel, W. and Kohler, H. (1972) Synthesis and rearrangement of V2V-dimethyl-0-(4-substituted-2,6-di-fert-butylphenyl)thiocarbamates. Chemische Berichte, 105, 1087-1091. 

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