Carbamate compounds

We have investigated Ce(IV) ion-carbamates, such as methyl and butyl 4-methylphenyl-carbamate, (MTC and BTC, respectively), or methyl, ethyl, and butyl phenylcarbamate, (MFC, EPC and BPC, respectively), systems for AAM polymerization [19]. It was found that the presence of carbamate compounds can promote the polymerization and enhance the rate of AAM polymerization (Rp) in descending order as ... 

In general, a nonspecific method is not acceptable because it is possible for the identity of the source of the analyte to be called into question. However, in cases where derivatization from a common species is the only method available (e.g., dithio-carbamate compounds), the use of a nonspecific common moiety method may be acceptable. 

Cobalt(III) complexes of formula cis- and trans-[Co(dtc)L4]2+ and [Co(dtc)2L2]+ where dtc = dimethyl-, diethyl- or piperidino-dithiocarbamate were prepared with phosphites P(OMe)3, P(OEt)3 and 4-ethyl-2,6,7-trioxa-l-phophabicyclo[2.2.2]octane as ligands L.1048 Whereas Co—P bonding is found, as defined in the crystal structures of each of the two forms of complexes isolated, a linkage isomer in which the phosphite is O bound was detected for the bis(dithio-carbamate) compounds. 

Smith, G.J. 1987. Pesticide Use and Toxicology in Relation to Wildlife Organophosphorus and Carbamate Compounds. U.S. Fish Wildl. Serv. Resour. Publ. 170. 171 pp. 

In the 1960s and 1970s, the organophosphate and carbamate compounds replaced the chlorinated hydrocarbons as the most prominently used insecticides. These two families of insecticides share a common toxicological mechanism, the inhibition of cholinesterase enzymes in the nervous systems of... 

For resin-bound ureas (22-25), Indole and Rink linkers, generally ranked 1 and 2 in cleavage kinetics, were still the most acid-labile linker for this class of compounds. Resins (24) and (25) were cleaved with 0.5% TFA in 2 and 23 min, respectively. Resins (22) and (23) were cleaved with 1% TFA in more than 10 h. The order of cleavage rates is similar to carbamate compounds. 

Pseudo-allyl compounds are formed from reactions of [Re(CO)2(PPh3)2(OCHNC6H4-4-Me)] with excess of PhNCO or PhNCS. Whereas carbamate compounds are formed in the former case, a mixture of monothio- and dithiocarbamate compounds is obtained with the sulfur analogue. The formation of the latter complex proceeds via the intermediate formation of the first. The related compounds show similar structural features with distorted octahedral rhenium atoms and... 

Figure 4.8 — Manifold used for implementation of the flow-through sensor developed for the determination of carbamate compounds based on hydrolysis of the analytes and dye formation, q flow-rate R reactor SV switching valve DAS diode array spectrophotometer W waste. (Reproduced from [98] with permission of the American Chemical Society).

Copolymers of ethylene vinylacetate are the most commonly utilized fuel wax crystal modifiers. Other compounds such as vinyl acetate-fumarate copolymers, styrene-ester copolymers, diester-alphaolefin copolymers, as well as alkyl carbamate compounds are effective wax crystal modifiers. These compounds differ in both chemical structure and in the extent of performance provided. See FIGURES 6-7 and 6-8. 

The amino group of 463 is transformed initially into carbamate compounds by treatment with several isocyanates. The carbamate intermediates were readily cyclized in base to give dihydrothieno[3,2-4]pyrimidines 464 (Equation 173) <1996MI597, 1995JOC1461>. 

Electrochemical detection is also possible for the HPLC determination of carbamate compounds capable of being oxidized or reduced at moderate electrode potentials (120). 

Both chemically and toxicologically, the most significant property of isocyanates is the high chemical reactivity of the isocyanate functional group. Industrially, the most significant such reaction is with alcohols to yield urethane (carbamate) compounds, as shown by reaction 15.8.2. Multiple... 

Carbaryl has been widely used as an insecticide on lawns or gardens. It has a low toxicity to mammals. Carbofuran has a high water solubility and acts as a plant systemic insecticide. It is taken up by the roots and leaves of plants so that insects feeding on the plant material are poisoned by the carbamate compound in it. 

For example, no difference in the toxicity of organophosphorus compounds to larvae of the midge Chrironomus riparius was observed between pulsed and continuous exposures (Kallander et al. 1997). In the same study, however, two 1-hour pulses caused significantly fewer symptoms of intoxication than 2 hours of continuous exposure to carbamate compounds, when animals were placed in clean water for at least 2 to 6 hours between treatments (Kallander et al. 1997), suggesting that detoxification or elimination of the toxicant during the toxicant-free period can reduce the toxic effects of the earlier exposures. 

Molecules which are not electrochemically active can be derivatized using an appropriate "electrophore", making the derivative eligible for electrochemical detection (9). It is fortunate that the nitrophenyl group, commonly used for UV and GC derivatization, is easily reducible. Methods based on the determination of intact carbamate residues by GC have been very disappointing as the result of thermal instability of a large majority of carbamate compounds. Therefore, a number of derivatization methods have been proposed. Carbamates, which produce an aromatic amine or phenol when hydrolyzed, were derivatized using 2,4-Dinitrofluorobenzene (DNFB) to form 2,4-... 

In parallel to these studies, carbamate compounds 1 and 11-14 were assessed for their antitumor efficacy in mouse cancer xenograft models.15 When implanted human colon cancer CXF280 xenografts were grown within mice for fourteen days, doses of test compounds were administered orally. After a three-week regimen, excised tumor volumes were measured and the percent inhibition of tumor growth was calculated. From this investigation, capecitabine (1) was found to be the most effective treatment, and was furthermore found not to cause intestinal toxicity.16 All of these preclinical observations contributed to the selection of capecitabine as a candidate for further development. 

Idriss, M.K., L.G. Agtrayo, D.L. Rickett, and E.X. Albuquerque. 1986. Organophosphate and carbamate compounds have pre- and postjunctional effects at the insect glutamatergic synapse. J. Pharmacol. Exp. Ther. 239 279-285. 

Fonnum, F., Sterri, S.H. (2006). Tolerance development to toxicity of cholinesterase inhibitors. In Toxicology of Organ-ophosphate and Carbamate Compounds (R.C. Gupta, ed.), pp. lSl-61. Elsevier Academic Press, San Diego, CA. 

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