Monomethyl-carbamates

Monomethyl carbamates hydrolyze more rapidly than dimethyl carbamates, because of the lesser steric congestion near the carbonyl. In addition, NH-contain-... 

The investigated carbamate insecticides were susceptible to chemical hydrolysis in alkaline media. The hydrolysis rates of the monomethyl-carbamates, Sevin and baygon, were much higher than those of the dimethylcarbamates, pyrolan and dimetilan. The pseudo-first order rate constants for hydrolyzing Sevin and baygon increased with the rise of the pH of the medium. 

Carbamates all have the general structure of RO(CO)NHCH3. It turns out that only carbamates with a monomethyl-substituted amine group are biologically active. Although these compounds are not widely used any more, there are two carbamates, the structures of which we should be aware. 

The application in the N-methylation of alkaloids has been published [SH3]. The N-methylation of amines by paraformaldehyde-NaBH4 in CF3COOH in the presence or absence of THF or by CH20-NaCNBH3 in AcOH has also been recommended [GN3]. However, this method is limited because it is not possible to make monomethylated amines from primary amines the transformation of the intermediate secondary amine to tertiary amine is very rapid [AC5]. The best way to prepare monomethylated amines is then via the carbamates (Section 3.2.8). 

The interaction of OPs and carbamates with the esteratic subsite is, thus, analogous with the interaction by the neurotransmitter. However, whereas the transmitter is easily and very quickly released from the esteratic active subsite (in about 40 microseconds), the carbamates are released more slowly, over several minutes. The k3 for a monomethyl carbamylated house fly brain AChE was 0.01 min-1, brain-1 (25 C, pH 7.4) (52.). Since the... 

Trioxane ethers (46 1-4) were as effective as the lower alkyl ethers of dihydroartemisinin except (46 1, R = CH3) [52]. From the size of the substituents of the trioxane ethers the benzyl ether was the most active. Trioxane carboxylate esters (47 1-6) and carbamate esters (47 7-9) were tested against W-2 and D-2 clones. The trioxane monomethyl... 

Numerous other metal complexes were studied by DTA/DSC and other TA techniques including Ni(II), Cu(II) and Co(II), and Co(II) diethyldithio-carbamate complexes (72) bis(2,4-pentanedionato)beryllium (II) and tris-(2,4-pentanedionato)aluminum (III) complexes (101) dihalogendi(tertiary-phosphine) cobalt (II) complexes (102) bis(trispyrrolidinophosphine oxide)-tetranitratouranium(IV) (103) Co(II), Cu(II), and Cd(II) xanthine complexes (104) and alkali and alkaline earth monomethyl violurates (105,108). 

First of all toluene is treated with chlorosulfonic acid to yield/ -toluenesulphonyl chloride, which on treatment with ammonia gives rise to the formation of/ -toluenesulphonamide. The resulting product on condensation with ethyl chloroformate in the presence of pyridine produces N-p-toluenesulphonyl carbamate with the loss of a mole of HCl. Further aminolysis of this product with butyl amine using ethylene glycol monomethyl ether as a reaction medium loses a mole of ethanol and yields tolbutamide. 

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