573-27-3Relevant articles and documents
Fluorovinloxyacetamides, process for preparing same and herbicidal composition comprising same
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, (2008/06/13)
Herbicidal fluorovinyloxyacetamide compounds of formula (I) are useful for protecting crops from weeds: wherein: R1is a phenyl group optionally having one or more substituents selected from the group consisting of C1-6alkyl, halogen-
Reactivite du nitrite de sodium. II. Action sur les sels d'iminium heterocycliques. Etude par RMN multinucleaire
Gouesnard, Jean-Paul,Dorie, Jean
, p. 253 - 258 (2007/10/02)
The structure and the electronic delocalisation of various heterocyclic iminium salts - and their precursors - have been studied by 13C and 15N NMR.The 13C and 15N chemical shifts are correlated with the nucleophilicity of the second heteroatom.The observation of δ13C explains satisfactorily the reactivity of heterocyclic iminium salts towards nucleophilic reagents and their catalytic activity as model compounds for thiamine or cocarboxylase.Different products are obtained by the reaction of sodium nitrite - in aqueous or non-aqueous medium - : they have been identified by NMR.The products are those expected and allow the determination of the reaction mechanisms.
Formation and Reactions of the Cyclic Tautomers of Tryptophans and Tryptamines. VII. Hydroxylation of Tryptophans and Tryptamines
Taniguchi, Mikio,Anjiki, Tomiko,Nakagawa, Masako,Hino, Tohru
, p. 2544 - 2554 (2007/10/02)
The 5-hydroxytryptophan derivative 12 was prepared in 60percent yield from the tryptophan derivative 8 by selective oxidation of the cyclic tautomer 9 with Fremy's salt or Pb(OAc)4-CF3COOH to the p-quinoneimine 10, followed by reduction and ring-opening.By analogous oxidation, serotonin was prepared from tryptamine.On the other hand, the oxidation of the Na-acetyl-cyclic tautomers (16 and 22) with Pb(OAc)4-CF3COOH followed by methylation gave the 5- and 6-methoxy derivatives (17, 18, 23, and 24) in 20-40percent yields.These compounds were readily converted to the 5- and 6-methoxytryptophan derivatives (20, 21) by acid treatment.These methods are the first practical hydroxylation procedures to be reported for tryptophans.Keywords: 5-hydroxytryptophan; methoxytryptophan; cyclic tautomer; tryptophan; oxidation; hydroxylation; lead tetraacetate; Fremy's salt.