S-Methyl-/V

J.D. Stenger-Smith, P. Zarras, L.H. Merwin, S.E. Shaheen, B. Kippelen, and N. Peyghambarian, Synthesis and characterization of poly(2,5-bis(A -methyl-/V-hexylamino)phcnylcnc vinylene), a conjugated polymer for light-emitting diodes, Macromolecules, 31 7566-7569, 1998. 

An alternative method for formation of trisulfides1 0 has been derived from well-known procedures for the formation of disulfides that involve sulfenyl thiocarbonates as protecting/ activating groups for cysteine 25 In analogy to the chemistry for disulfides, cysteine side chains were protected and activated as extra-sulfur analogues, i.e. as S-(methoxy-carbonyl)disulfanyl or S-(/V-methyl-/V-phenylcarbamoyl)disulfanyl derivatives 10 Preferably,... 

Extension of this elimination to the similar -hydroxy sulfoximines 5 having a chiral bicyclic ring system which can be obtained in a similar way from the corresponding chiral ketone and (R) or (.S )-.S -lithiomethyl-/V-methyl-5 -phenylsulfoxime, leads to the formation of the diastereomeric alkenylsulfoximines 6 in the same diastereomeric ratio of S 98 2. The steric course of the elimination of these /i-hydroxy sulfoximines is determined by the configuration of the sulfoximine group. 

Iod- bzw. 4-Iod-l-methyl-imidazol reagieren mit Kupfer-Alkin-Komplexen zu 2- (bzw. 4)-(l-Alkinyl)-l-methyl-imidazolen (s.Bd. V/2a, S. 572). 

Kim, D. J., B. W. Ahn, B. S. Han, and H. Tsuda. 1997. Potential preventive effects of Chelidonium majis L. (Papaveraceae) herb extract on glandular stomach tumor development in rats treated with V-methyl-V -nitro-V nitrosoguanidine (MNNG) and hypertonic sodium chloride. Cancer Lett. 112 203-208. 

Lawley, P.D.. Orr, D.J. Shah. S.A. (1972) Reaction of alkylating mutagens and carcinogens with nucleic acids N3 of guanine as a site of alkylation by V-methyl-V-nitrosourca and dimethyl sulphate. Chem.-biol. Interact., 4, 431-434... 

Hirose, M., Yamaguchi, S., Fukushima, S., Hasegawa, R., Takahashi, S. Ito, N. (1989) Promotion by dihydroxybenzene derivative of V-methyl-V -nitro-A-nitrosoguanidine-induced F344 rat forestomach and glandular stomach carcinogenesis. Cancer Res., 49, 5143-5147... 

Urinary metabolites are S-methylthioacetic acid sulfoxide, V-acetyl-.S -methyl-L-cysteine and /-(methylthioacetyl)glycine, which are metabolites of Y-methyl-i-cysteine and 5-methylglutathione. These last two compounds were found after incubation of methyl chloride with rodent liver, kidney and brain homogenates. The methyl group of methyl chloride is metabolized via -methyl-L-cysteine to formate which is found in urine and blood of rats, whereas formaldehyde is found in rat liver microsomes and blood of mice and rabbits (lARC, 1986). 

Reddy, B.S., Weisburger, J.H., Narisawa, T. Vender, E.L. (1974) Colon carcinogenesis in germ-free rats with 1,2-dimethylhydrazine and A-methyl-V -nitro-A-nitrosoguanidine. Cancer Res., 34, 2368-2372... 

Frei. J.V. Venitt. S. (1975) Chromosome damage in the bone marrow of mice treated with the methylating agents methyl methanesulphonate and V-methyl-V-nitrosourea in the presence or absence of caffeine, and its relationship with thymoma induction. Mutat. Res., 29, 89-96... 

This work has been extended from aryl and alkyl substituted systems (42) (R=aryl, alkyl) to analogues where R is an amino group, so giving access to synthetic equivalents of the nonstabilized amino nitrile ylides (45). Adducts were obtained in good-to-moderate yield with /V-methylmaleimide (NMMA), DMAD, electron-deficient alkenes and aromatic aldehydes (27,28), and with sulfonylimines and diethyl azodicarboxylate (29). Similarly the /V-[(trimethylsilyl)methyl]-thiocarbamates (46) undergo selective S-methylation with methyl triflate and subsequent fluorodesilylation in a one-pot process at room temperature to generate the azomethine ylides 47. 

Biosynthesis. The terminal C methyl of the propyl side chain, the S-methyl. and the /V methyl groups are derived from methionine, trans-4-Propyl-L-proline was shown to accumulate when Strepromyces lincolnensis is grown in media deficient in sulfur, and the addition of T. tyrosine or L-dihydroxyphenylalaiiine (DOPA) was shown to stimulate this production. 

The following qualitative observations on the action of liquid ammonia on organic compounds are mainly by E. C. Franklin and C. A. Kraus, those in brackets are by G. Gore. Aliphatic compounds.—Halides methyl iodide, m. chloroform, reacts, and m. bromoform, m. iodoform, v.s., ethyl bromide and iodide, s. ethylene bromide, s. ethylidene chloride, m. isobutyl bromide, s. amyl bromide, s.s. tribromomethane, v.s. nitrotriohloromethane, m. perehloroethane (n.s.) perchloroethylene (m.) dichloroacetylene (s.). Alcohols methyl, m. ethyl, m. propyl, m. normal butyl,... 

Alkaline hydrolysis of benzal acetone structures to the corresponding aldehyde (XIX) and acetone and subsequent oxidation of the aldehyde (XIX) to the corresponding benzoic acid (V) do not seem to represent an actual degradation stage since oxidizing the aldehyde (XIX) under our mild standard conditions yielded only traces of the corresponding benzoic acid (V). The aldehyde (XIX) was rapidly decomposed via Dakin reaction to formic acid and 3-methoxy-S-methyl-o-benzoquinone, which is immediately degraded to phenolic humic compounds. 

In 2005, a diastereoselective synthesis of m-3-alkyl-l-benzyl-4-ethoxycarbonyl-[S-1 act a ms has been reported to be developed by galvanostatic electrolysis of a solution of acetonitrile containing a tetraalkylammonium salt, as supporting electrolyte and /V-(ethoxycarbonyl)methyl-/V-benzyl-2-bromoalkylcarboxamides [165]. The electrogenerated cyanomethyl anion, at room temperature and under a nitrogen atmosphere, caused the cyclization of the substituted carboxamides. High cis/trans ratios were observed with all the substrates exploited, (Scheme 68). 

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