89-00-9Relevant articles and documents
The pyridine ring of NAD is formed by a nonenzymatic pericyclic reaction
Colabroy, Keri L.,Begley, Tadhg P.
, p. 840 - 841 (2005)
The biosynthesis of quinolinate 3, the precursor to the pyridine ring of NAD, is still poorly understood. Two pathways have been identified, one involving the direct formation of quinolinic acid from aspartate and dihydroxyacetone phosphate, the other requiring a five-step degradation of tryptophan. The final step in this degradation is catalyzed by the non-heme Fe(II)-dependent enzyme 3-hydroxyanthranilate-3,4-dioxygenase (HAD). This enzyme catalyzes the oxidative ring opening of 3-hydroxyanthranilate (1) to 2-amino-3-carboxymuconic semialdehyde (ACMS, 2) which then cyclizes to quinolinate (3). In this communication, we demonstrate the following: (1) cyclization of ACMS to 3 is not HAD catalyzed, (2) the most stable form of ACMS in solution is an all trans isomer which undergoes facile cis to trans isomerization about the C2-C3 and C4-C5 double bonds via transient formation of its enol tautomer (6), (3) a model study on the ring opening of N,N-dimethylcarbamoylpyridinium with hydroxide and methoxide suggests that the cyclization of ACMS occurs by an electrocyclization reaction of its enol tautomer 6. Thus, the biosynthesis of quinolinic acid, by the tryptophan pathway, is likely to be a member of a growing family of natural products whose biosynthesis involves a pericyclic reaction. Copyright
Method for preparing nitrogen-containing six-membered ring dicarboxylic acid
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Paragraph 0033-0035; 0037, (2020/04/22)
The invention relates to compound preparation, particularly to a method for preparing nitrogen-containing six-membered ring dicarboxylic acid from a benzo nitrogen-containing six-membered ring compound. According to the method, a raw material compound and a sodium chlorate aqueous solution are catalyzed under an acidic condition to obtain nitrogen-containing six-membered ring dicarboxylic acid, wherein the raw material is a nitrogen-containing six-membered heterocyclic benzocyclic compound. According to the invention, the catalyst of the reaction system is low in toxicity and low in cost, no new impurity is generated in the post-treatment step, and large-scale production is facilitated.
A 2, 3 - pyridine dicarboxylic acid synthesis method
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Paragraph 0009; 0010; 0011; 0012; 0013-0030, (2019/01/08)
The invention discloses a 2, 3 - pyridine dicarboxylic acid synthesis method, CuSO4 · 5 H2 O, sulfuric acid, benzo pyridine sodium chlorate, to aldehyde benzoic acid methyl ester, pyrrole, H2 TCPP - OMe, MnCl2 · 6 H2 O as the main raw material, the synthesis process of the present invention benzo pyridine first NaClO in oxidation system3 - H2 SO4 - CuSO4 The catalyst under Mn - TCPP oxidation under the action of the open loop, after alkali hydrolysis, acidifying the resulting 2, 3 - pyridine dicarboxylic acid. For Mn - TCPP catalyst benzene ring and the double bond is connected to the electron-donative group, double bond can be increased on the electron cloud density, more easily reactant intermediate attack activation, therefore open-loop oxidation effect can be improved, so that the yield is obviously higher than the traditional potassium permanganate oxidation product yield.
