13473-01-3Relevant articles and documents
Preparation method of 2,5-dimethoxy pyridine
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Paragraph 0142; 0143; 0144; 0145, (2018/12/13)
The invention discloses a preparation method of 2,5-dimethoxy pyridine, and belongs to the technical field of medicine synthesis. The method comprises the following steps that 1, under the existence of an alcohol solvent, a compound shown as a formula A and sodium methoxide take contact reaction to form a compound shown as a formula B; 2, under the existence of metal catalysts, the compound shownas a formula B in the first step reacts to obtain 2,5-dimethoxy pyridine; aftertreatment and purification are performed to obtain the product. The method has the advantages that the route is short; the steps are few; expensive palladium catalysts and boracic acid catalysts are not used; the equipment cost is reduced; the use of flammable and explosive lithium reagents and peroxide is avoided; thereaction conditions are mild; the aftertreatment operation is simple and convenient; the total yield and the purity are improved; the product quality can be easily controlled; the industrial amplification prospects are good.
PYRROLIDINES AS NK3 RECEPTOR ANTAGONISTS
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, (2011/04/14)
The present invention relates to a compounds of formula I wherein R1, R2, Ar1, Ar2, R′, R″, m, n, and o are defined in the specification or to a pharmaceutically active salt, racemic mixture, enantiomer, optical isomer or to tautomeric form thereof. The present compounds are high potential NK-3 receptor antagonists for the treatment of depression, pain, psychosis, Parkinson''s disease, schizophrenia, anxiety and attention deficit hyperactivity disorder (ADHD).
Substituted 3,4-pyridynes: Clean cycloadditions
Connon, Stephen J.,Hegarty, Anthony F.
, p. 1245 - 1249 (2007/10/03)
The stabilisation of 3,4-pyridyne (1) by an alkoxy group adjacent to the ring nitrogen is reported. The regioselective lithiation of 2-ethoxy- (14), 2-methoxy- (18), 2-isopropoxy- (19) and 6-isopropoxy- (26) -3-chloropyridines with tertbutyllithium at low temperatures, followed by elimination of lithium chloride affords 2- and 6-alkoxy-3,4-pyridynes. These species are trapped m situ with furan in a Diels-Alder reaction to give 5-8 in 66-89% yield, and do not give products typical of polymerisation or nucleophilic addition to the 3,4-pyridyne intermediates. As a comparison treatment of 3-chloropyridine with furan and LDA gives only 19% of adduct (4). We also report the novel use of the isopropoxy (rather than methoxy) group in these systems, which can act as a heteroatomic electron donating group which inhibits a-lithiation by tert-butyllithium because of its increased steric bulk. The Royal Society of Chemistry 2000.