1-Benzyl-5-nitro

A new photoactive monoclinic polymorph of 6-(2, 4 -dinitrobenzyl)-2,2 -bipyri-dine was obtained from an acetone/methanol solution, and the structure compared to the previously known photoactive orthorhombic and photoinactive monoclinic forms [94]. Correlation of these structures with those of related nitrobenzylpyridines was used to understand the relationships existing between structure and photochro-mism. The comparison of the reaction cavities around the reactive pyridyl-benzyl-nitro fragment indicated that photochromic activity required rotational freedom of the ortho-nitro group in the crystal and its accessibility from the proton-donor and proton-acceptor sites. 

Electrochemical reduction of benzylic nitro compounds (27) in an ethanolic aqueous acetic acid buffer (35 65) affords a mixture of the corresponding oxime and hydroxylamine (equation 6)48. The hydroxylamine can subsequently be oxidized back to the oxime (28) (via the intermediate nitroso compound) conversions as high as 90% can be obtained. 

Methyl-(4-methyl-benzyl)-nitro-E16a. 1161 (N-Alkylier.) Methyl-nitro-(2-phenyl-ethyl)- E16a, 1159 (NO - N02)... 

Amin (4-Methoxy-benzyl)-nitro-propyl- EI6a, 1161 (N-Alkylier.) Benzoesaure 4-Amino-2-hydroxy- -(2-dimethylamino-ethylester) Vl/lc, 403... 

A benzylic nitro group is hydrogenolyzed in the presence of Pd(OH)2, whereas homogeneous catalysts are ineffective and only low conversion is observed with Pt/C (and with Rh/C hydrogenation to amines occurs). In conjunction with an enantioselective Henry reaction, chiral homobenzyhc alcohols are accessible. 

Triethylsilane in the presence of a Lewis acid catalyst has been found to reduce a-nitrosulfides to thio ethers67 (equation 60). The / -nitrosulfides are reduced with rearrangement (equation 61). Benzyl nitro systems are also reduced under these conditions. Tri-n-butyltin hydride is still the best reagent for the reduction of alkyl nitro compounds, but in these instances it would reduce the thiophenoxy group as well. 

The SrnI reaction also proceeds with tertiary benzyl nitro compounds lacking a p-nitro substituent. The nitro group at the benzyl position acts as the electron acceptor, and decomposes to the benzyl radical and nitrite anion. The nitronate anion nucleophiles are then alkylated. Entry 5 in Scheme 12.7 provides a specific example. 

This reaction also can be made to proceed with tertiary benzyl nitro compounds lacking the p-nitro substituent. The nitro substituent at the benzyl position provides sufficient stabilization to permit the electron transfer to proceed, generating the radical anion. This species decomposes to a tertiary benzyl radical by loss of nitrite ion. Substituted nitrocumyl systems can alkylate nitronate anions in HMPA sol-... 

The free radical condition with w-BusSnH/AIBN in benzene has been employed to replace the nitro group with the hydrogen atom in 2-nitroalcohol 42 with excellent diastereoselectivity. On the other hand, secondary benzylic nitro group of 2-nitroalcohol 44 can be reduced to afford homobenzylic alcohol 45 by hydrogenation catalyzed by Pearlman s catalyst... 

Bromobenzene, iodobenzene and benzyl chloride behave somewhat similarly. The />-nitro-derivatives of the first two compounds frequently crystallise out even before pouring into water p-nitrobenzyl chloride usually remains as an oil for several minutes before solidifying. 

Drop 1 g. of sodium into 10 ml. of ethyl alcohol in a small flask provided with a small water condenser heat the mixture until all the sodium has dissolved. Cool, and add 1 g. of the ester and 0-5 ml. of water. Frequently the sodium salt of the acid will be deposited either at once or after boiling for a few minutes. If this occurs, filter oflF the solid at once, wash it with a little absolute ethyl alcohol (or absolute methylated spirit), and convert it into the p-bromophenacyl ester, p-nitro-benzyl ester or S-benzyl-tso-thiuronium salt (for experimental details, see Section 111,85). If no solid separates, continue the boiling for 30-60 minutes, boil oflF the alcohol, allow to cool, render the product just neutral to phenolphthalein with dilute sulphuric or hydrochloric acid, convert the sodium salt present in solution into a crystalline derivative (Section 111,85), and determine its melting point. 

Acid B.P. H.P. AnlUde p-Tolu4- dide 1 Amide p-Bromo- phenacyl ter p-Nitro- benzyl Ester p-Phenyl phenacyl Ester S-Benzyl- uo-thi- uronium Salt Other Derivatives... 

The argtiments of Norman and his co-workers seem to give affirmative answers to the first and second of these questions, but it is doubtful if the available data further require such an answer for the third question. It can be argued that the crucial comparison made between the behaviour of benzyltrimethylammonium ion and protonated benzyl methyl ether is invalid, and that it is possible to interpret the results in terms of nitration by the nitronium ion, modified by protonation of the oxygen atom of the ether a case for the possible involvement of the nitro-nium ion in specific interaction leading to o-substitution has been made. ... 

CbEOROCARBONSANDCbEOROHYDROCARBONS - BENZYL CbEORIDE, BENZAL CbEORIDE AND BENZOTRICbEORIDE] (Vol 6) 4-Nitro-3-(trifluoromethyl)phenol [88-30-2]... 

Tertiary, benzyl, and aHyhc nitro compounds can also be used as Friedel-Crafts alkylating agents eg, reaction of (CH2)3CN02 (2-nitro-2-methyl propane [594-70-7]) with anisole in the presence of SnCl gives 4-/-butylanisole [5396-38-3] (7). SoHd acids, such as perfluorodecanesulfonic acid [335-77-3], and perfluorooctanesulfonic acid [1763-23-1] have been used as catalysts for regio-selective alkylations (8). 

Benzyl saUcylate can be prepared by the reaction of ben2yl chloride with an alkaU salt of saUcyhc acid at 130—140°C or by the transesterification of methyl saUcylate with benzyl alcohol. It is used as a fixative and solvent for nitro musks and as a fragrance for detergents. Benzyl saUcylate was priced at... 

Imidazolidin-2-one, l-(5-nitro-2-thiazolyl)-pharmacological activity, 6, 328 Imidazolidin-4-one, l-aryl-3-phenyl-2-thioxo- C NM S, 355 Imidazolidinones C NMR, 5, 355 Imidazolidin-2-ones nucleophilic displacement, 5, 428 polymers, 1, 279-280 reactivity, 5, 376 synthesis, 5, 466, 471 Imidazolidin-4-ones synthesis, 5, 468 Imidazoline, 2-alkyl-synthesis, 5, 463 Imidazoline, 2-amino-applications, 5, 498 Imidazoline, 2-aryl-synthesis, 5, 463 Imidazoline, 2-methyl-synthesis, 5, 487 Imidazoline, 2-nitroamino-synthesis, 5, 471 2-Imidazoline, 2-arylamino-tautomerism, 5, 368 2-Imidazoline, 1-benzyl-methylation, 5, 425 2-Imidazoline, 1,2-diaryl-synthesis, 5, 463... 

Pyrimidine, 5-benzyl-4,6-dimethyl-2-phenyl-synthesis, 3, 118 Pyrimidine, 2-benzyl-5-nitro-synthesis, 3, 130 Pyrimidine, benzyloxy-pyrimidinone synthesis from, 3, 133 Pyrimidine, 4,5-bis(alkylamino)-synthesis, 3, 121 Pyrimidine, 2-bromo-aminolysis, 3, 100 H NMR, 3, 62 reactions... 

Theophylline, 9-aryl-synthesis, 5, 576 Theophylline, 8-arylamino-synthesis, 5, 576 Theophylline, 9-benzyl-rearrangement, 5, 534 Theophylline, 8-chloro-reduction, 5, 541 Theophylline, 6-deoxy-reduction, 5, 541 Theophylline, 8-dimethylamino-synthesis, 5, 580 Theophylline, 8-methyl-synthesis, 5, 591 Theophylline, 8-methylthio-synthesis, 5, 578 Theophylline, 8-nitro-synthesis, 5, 538 Theophylline, 7-phenyl-synthesis, 5, 581 Theophylline, 8-phenyl-7-oxide... 

The cleavage proceeds by initial reduction of the nitro groups followed by acid-catalyzed cleavage. The DNB group can be cleaved in the presence of allyl, benzyl, tetrahydropyranyl, methoxy ethoxy methyl, methoxymethyl, silyl, trityl, and ketal protective groups. 

The 2,6-dimethylbenzyl ether is considerably more stable to hydrogenolysis than is the benzyl ether. It has a half-life of 15 h at 1 atm of hydrogen in the presence of Pd-C whereas the benzyl ether has a half-life of —45 min. This added stability allows hydrogenation of azides, nitro groups, and olefins in the presence of a di-methylbenzyl group. ... 

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