100907-37-7Relevant articles and documents
PREPARATION OF PYRIDINE DERIVATIVES USING PYRIMIDINIUM DERIVATIVES AS INTERMEDIATES
-
Page/Page column 23-24, (2008/06/13)
A method in which a pyridinium derivative of formula (I) such as 1,3-dimethyl-2,3-dihydro-2-oxopyrimidinium chloride is reacted with an acetyl compound of formula (II) such as 4-acetylpyridine, and then the reaction product is reacted with ammonia or an ammonium salt to form a pyridine derivative of formula (III):Also disclosed is a method for the preparation of the compound of formula (I) from reacting a compound of formula (IV) or (V) with a compound of formula (VI):Also disclosed are two additional alternative methods for the preparation of compounds of formula (I) and related compounds. The substituents are defined in the claims.
Organic Syntheses via Transition Metal Complexes, 61. - Pyridines and Pyridinium Salts from (β-Aminovinyl)carbene Complexes (M = Cr, W) and Alkynes via 4(1H)-Pyridinylidene Complexes
Aumann, Rudolf,Hinterding, Peter
, p. 2765 - 2772 (2007/10/02)
Pyridines and pyridinium salts were obtained in good yields by the condensation of (β-aminovinyl)carbene complexes with alkynes.The reaction of carbene complexes LnM=C(OEt)CH=CRNHR1 (Z)-6a - f (R,R1 = Ph, Me, iPr, nBu, CH2Ph, CH2OMe) with alkynes R2CCH 7a - c (R2 = nBu, Ph, CH2OMe) involves the highly regioselective formation of 4(1H)-pyridinylidene complexes 8a - j nM = (CO)5Cr, (CO)5W>.Protonation of 8 with HBF4 leads to pyridinium salts 13 by the regiospecific substitution of the metal moiety LnM by a proton.The reaction may conveniently be performed in a one-pot procedure. carbene>chromium complexes, e.g. 14, react with alkynes to give pyridines, e.g. 15.The thermal decomposition of 6 yields enol ethers 11.A regiospecific formation of (E)-11 is observed in the thermolysis of 6 in the presence of pyridine. Key Words: β-Aminovinylcarbene complexes of chromium and tungsten / 4(1H)-Pyridinylidene complexes / Pyridines via alkenyl carbene complexes and alkynes / Pyridinium salts via vinyl carbene complexes and alkynes / Enol ethers from β-aminovinylcarbene complexes
SYNTHESIS OF 2-(4-n-ALKYLPHENYL)-5-n-AKLYLPYRIDINES
Pavlyuchenko, A. I.,Smirnova, N. I.,Korotkova, N. I.,Kovshev, E. I.
, p. 1143 - 1144 (2007/10/02)
New liquid-crystalline 2-(4-alkylphenyl)-5-alkylpyridines were synthesized by the reaction of 2-(4-alkylphenyl)-1-lithio-1,2-dihydropyridines with alkyl bromides.The compounds obtained have relatively low melting points and narrow temperature ranges of the existence of a nematic meso phase; the thermal stability of the meso phase is determined by the lenght of the alkyl group in the pyridine and benzene parts of the molecule.
