3 Methyl 4 nitropyridine 1 oxide

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

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. 

Lipscomb, G. F., Garito, A. F., and Narang, R. S., An exceptionally large linear electro-optic effect in the organic solid MNA, J. Chem. Phys., 75, 1509 (1981). Sigelle, M, and Hierle, R., Determination of the electrooptic coefficients of 3-methyl 4-nitropyridine 1-oxide by an interferometric phase-modulation technique, J. Appl. Phys., 52, 4199 (1981). 

Reactions using picoline 1-oxides have been less successful than those using picolines. 2- and 4-Picoline 1-oxides did not react with aromatic aldehydes under various acidic and basic conditions, 199 but poor yields of stilbazole oxides were obtained using piperidine acetate in boiling tolu-ene . Under these conditions, the picolines performed no better than their oxides. 3-Methyl-4-nitropyridine 1-oxide reacted with benzaldehyde in presence of piperidine, circumstances under which 3-methyl-4-nitropyridine did not reacti 3 More successful have been reactions of the oxides catalysed by metal alkoxides or hydroxides (p. 383). 

Gu, F.L., Guillaume, M., Botek, E., Champagne, B., Castet, F., Ducasse, L., Aoki, Y Elongation method and supermolecule approach for the calculation of nonhnear susceptibilities. Application to the 3-methyl-4-nitropyridine 1-oxide and 2-methyl-4-nitroaniline crystals. J. Comput. Meth. Sci. Eng. 6, 171-188 (2006)... 

Amine oxides, prepared to protect tertiary amines during methylation and to prevent their protonation in diazotized aminopyridines, can be cleaved by reduction (e.g., SO2/H2O, 1 h, 22°, 63% yield H2/Pd-C, AcOH, AC2O, 7 h, 91% yield Zn/HCl, 30% yield). Photolytic reduction of an aromatic amine oxide has been reported [i.e., 4-nitropyridine A-oxide, 300 nm, (MeO)3PO/CH2Cl2, 15 min, 85-95% yieldl. ... 

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. 

The ortho indirect deactivating effect of the two methyl groups in 2,6-dimethyl-4-nitropyridine 1-oxide (163) necessitates a much higher temperature (about 195°, 24 hr) for nucleophilic displacement of the nitro group by chloride (12iV HCl) or bromide ions N HBr) than is required for the same reaction with 4-nitropyridine 1-oxide (110°). With 5-, 6-, or 8-methyl-4-chloroquinolines, Badey observed 2-7-fold decreases in the rate of piperidino-dechlorination relative to that of the des-methyl parent (cf. Tables VII and XI, pp. 276 and 338, respectively). 

Tile same methodology as mentioned for the preparation of (9) was applied for the synthesis of 8-nitro-l,6-naphthyridines. Heating diethyl N- 3-nitropyridin-4-yl)aminomethylenemalonate (12) in diphenyl ether yields ethyl 8-nitro-l,6-naphthyridin-4(lH)-one 3-carboxylate (13) (63JCS4237, 30%) and acid treatment of 4-( y, y-diethoxypropylamino)-5-nitro-2-(/3,/3 -trifluoroethoxy)-pyridine (14) gives in a similar way 8-nitro-5-(/3, /3-triflu-oroethoxy)-l,2-dihydro-l,6-naphthyridine (15, 76%). Subsequent oxidation with chloranil, acid hydrolysis, and methylation with methyl iodide gives 8-nitro-6-methyl-l,6-naphthyridin-5(6H)-one (16,63%) (81JHC941). 

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

In nitroamine oxides the nitro group may be reduced preferentially but usually both functions are affected. 5-Ethyl-2-methyl-4-nitropyridine A -oxide is converted quantitatively to 4-amino-5-ethyl-2-methylpyridine by hydrogen over 30% palladium on charcoal in ethanolic solution [737]. The outcome of the hydrogenation of a nitroamine oxide may be influenced by reaction conditions [736]. 

With methyl-3-nitropyridine iV-oxides, use of selenium dioxide results in complete oxidative demethylation (80TL2433). In isoquinoline methyl groups at positions 1 and 3 are efficiently oxidized to the corresponding aldehyde with selenium dioxide. 

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... 

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