3-METHYL-4-NITROPYRIDINE

METHYL-4-NITROPYRIDINE-1-OXIDE (3-Picoline, 4-nitro-, 1-oxide)... 

Methyl-4-nitropyridine-l-oxide has been prepared by the nitration of 3-methylpyridine-l-oxide hydrochloride with a mixture of concentrated sulfuric acid and potassium nitrate. The I)reparation of this compound has been mentioned briefly by Talikowa, but no experimental details have been given. 

See 3-Methyl-4-nitropyridine /V-oxide Acetic acid, Jute... 

Having established that the end game of the proposed synthesis of cylindrospermopsin (1) from bromoketone 4 was viable, we turned our attention to the preparation of acetylene 5 from 4-methoxy-3-methylpyridine (7). 4-Methoxy-3-methylpyridine (7) was prepared by modifications of the literature procedure.17,18 3-Methyl-4-nitropyridine A-oxide (27),19 was treated with K2CO3 in methanol at 70 °C to displace the nitro group to... 

POM (3-methyl-4-nitropyridine-N-oxide) 53) is the only commercially available organic crystal for SHG, other... 

Methyl-4-nitropyridine N-oxide, 2310 A-Methyl-A-nitrosourea, 0871 Methylnitrothiophene, 1844... 

Methyl-4-nitropyridine AAoxide, 2310 N-Methylmorpholine oxide, 1991 iV-Methylpiperidine —N /i-oxide, 2522... 

Methyl-4-nitropyridine A -oxide, 2310 2-Methyl-5-nitrobenzenesulfonic acid, 2768 Methylborylene, 0424 Methylnitrothiophene, 1844... 

Fig. 17. (a) Orientation of molecular dipole moments in 3-methyl-4-nitropyridine. Y-oxide fih molecular dipole moment from direct integration methods fi2, from multipolar model and Hj from semi-empirical calculation, (b) Electrostatic potential around the molecule in the plane of ring atoms. Contours at 0.2kcal/mol (reproduced with permission from Hamazaoui et al. [79]). 

Hypervalent Cl Sn—Cl bridges are also typical for pentacoordinate tin atoms. For example, the crystal structure of 20 and 21 comprise dimeric pairs of molecules bridged by weak intermolecular Cl Sn interactions. The Cl —Sn distances in 20 (2.475 A ), 21 (average 3.869 A ) and in MeSn(Ar)Cl2 (Ar = 3-methyl-4-nitropyridine-N-oxide) (3.934 A ) are longer than in most comparable structures The Sn NMR resonance (—285.7 ppm) for 21 suggests that it possesses a five-coordinate structure in solution . 

The well-known NLO molecular crystal POM (3-methyl-4-nitropyridine-1-oxide) is simulated through cluster calculations by Guillaume et al.216 Semi-empirical and MP2 ab initio results are considered and comparisons of the NLO response with those obtained from the usual oriented gas model are made. POM is also selected by Hamzaoui et al 11 as an example of an NLO molecular crystal on which to test their procedure for relating the polarizabilities to the multipolar components of the ground state charge distribution determined by X-ray diffraction methods. 

Nitro-3-picoline (MI-368) is hydrolyzed on standing to l-(3 -methyl-4 -pyridyl)-3-methyl-4-pyridone and 3-methyl-4-pyridone. 4-Nitropyridine and benzyl bromide give iV-benzyl-3,5-dibromo-4-pyridone (MI-369) in 33% yield. The quaternary salt first formed is hydrolyzed to the 4-pyridone. Oxidation of hydrogen bromide by the nitrous acid product provides the bromine and water. The yield is increased to 71%by the addition of bromine. 3,5-Dibromo-4-chloro-pyridine and benzyl bromide in base also give XII-369. Similarly, 3-methyl-4-nitropyridine and benzyl bromide give W-benzyl-3-bromo-5-methyl-4-... 

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