2-nitrobenzyl

Chlorophenyl 2-nitrobenzyl ether [109669-56-9] M 263.7, m 69 . Crystd from EtOH. 

Nitrophenyl)ethyl Carbamate. The photolytic removal of this group occurs twice as fast as does the 2-nitrobenzyl carbamate. Additionally, substitution at the alpha carbon increases the rate of cleavage even more. 

Nitrobenzyl, 684 4-Nitrobenzyl, 685 2,4-Dinitrobenzyl, 685 4-Chlorobenzyl, 685 4-Chloro-2-nitrobenzyl, 685... 

R = 3,5-dinitrophenyl, 2-nitrobenzyl, 3,5-dimethoxybenzyl, pyrenyl-methyl, desyl, 4-methoxybenzoylmethyl... 

Cleavage of an 5-2-nitrobenzyl phosphorothioate is achieved with thiophen-... 

The 4-chloro-2-nitrobenzyl group was useful in the synthesis of dithymidine phosphorothioates. It could be cleaved with a minimun of side reactions with PhSH, TEA. Pyr. ... 

Most of the widely used antidepressants are tricyclics related to imipramine. A 1-phenyltetrahy-droisoquinoline analogue, nomifensine (60), departs from this structural pattern. Hiarmacologi-cally it inhibits the reuptake of catecholamines such as dopamine at neurons. It can be synthesized by alkylation of 2-nitrobenzyl-methylamine with phenacyl bromide followed by catalytic reduction of the nitro group (Pd-C) and then hydride reduction of the keto moiety to give 59. Strong acid treatment leads to cyclodehydration to nomifensine (60) [17]. 

A similar synthesis starting with l-(2-nitrobenzyl)pyrrol-2-aldehyde used ethanol-ethyl acetate as solvent (62). Indoles are prepared in excellent yield by hydrogenation of o-nitrobenzyl ketones over Pd-on-C (i). Azaindoles are correspondingly prepared from nitropyridines (97). 

A solution of N-(2-aminobenzvl)-1-phenyl-2-metKylaminoethanol-1 was prepared by the reaction of a-bromo-acetophenone and (2-nitrobenzyl)methylamine, followed by hydrogenation of the nitro group by means of nickei on diatomaceous earth at room temperature and reduction of the CO group by means of sodium borohydride. The intermediate thus produced was dissolved in 100 ml of methylene chloride and introduced dropwise into 125 ml of sulfuric acid at 10° to 15°C. After a short standing, the reaction mixture was poured onto ice and rendered alkaline by means of a sodium hydroxide solution. Dy extraction with ether, there was obtained 1,2,3,4-tetrahydro-2-methyl-4-phenyl-8-amino-iso-quinoline. The base is reacted with maleic acid to give the maleate melting point of the maleate 199° to 201°C (from ethanol). 

The chemistry of indium metal is the subject of current investigation, especially since the reactions induced by it can be performed in aqueous solution.15 The selective reductions of ethyl 4-nitrobenzoate (entry 1), 2-nitrobenzyl alcohol (entry 2), l-bromo-4-nitrobenzene (entry 3), 4-nitrocinnamyl alcohol (entry 4), 4-nitrobenzonitrile (entry 5), 4-nitrobenzamide (entry 6), 4-nitroanisole (entry 7), and 2-nitrofluorenone (entry 8) with indium metal in the presence of ammonium chloride using aqueous ethanol were performed and the corresponding amines were produced in good yield. These results indicate a useful selectivity in the reduction procedure. For example, ester, nitrile, bromo, amide, benzylic ketone, benzylic alcohol, aromatic ether, and unsaturated bonds remained unaffected during this transformation. Many of the previous methods produce a mixture of compounds. Other metals like zinc, tin, and iron usually require acid-catalysts for the activation process, with resultant problems of waste disposal. 

C H,, N203 85660-33-9) see Nomifensine 7V-methyl-lV-(2-nitrobenzyl)phenacylamine (C (,H 9N203 102436-67-9) see Nomifensine 2-methyl-5-nitro-4,6-dihydroxypyrimidine (C5H5N3O4 53925-27-2) see Moxonidine 2-methyl-5-nitroimidazole... 

C2oHi(,ClN30ftS2 53483-68-4) see Cefaclor (2-nitrobenzyl)(cyciohexyl)methylamine (C14H20N2O2 80638-08-0) see Bromhexine 4-nitrobenzyl 3-hydroxy-7(/f)-phenyIacetamidocepham-4-carboxylate... 

P 59] A third protocol differed from [P 57] and [P 58] by sequential insertion of all reactants instead of using a pre-mixed solution of nitrobenzyltriphenyl-phosphonium bromide and sodium methoxide. As above, flow was fed by electroosmotic means [13]. A 40 pi volume of a methanol solution of 0.01 M 2-nitrobenzyl-triphenylphosphonium bromide was filled into the first reservoir, 40 pi of a methanol solution of 0.015 M sodium methoxide in the second, 40 pi of a methanol solution... 

OS 78] [R 4a] [P 58] The Wittig reactions of five aldehydes with 2-nitrobenzyl-triphenylphosphonium bromide were investigated also at a 1 1 stoichiometric ratio [13]. Using optimized reaction conditions, improved yields were found for four of the five aldehydes. 

Reduction of substituted 2-nitrobenzoic acid to 2-nitrobenzyl alcohol Sterling Organics Amery et al. (1993)... 

Previous syntheses An example of this point can be recognized by examination of one known synthesis of thienobenzazepines (Scheme 6.1). This synthetic route involves a key palladinm-catalyzed cross-conpling of stannyl intermediate 3, prepared by method of Gronowitz et al., with 2-nitrobenzyl bromide. Acetal deprotection and reductive cyclization afforded the desired thienobenzazepine tricycle 4. In support of structure activity relationship studies, this intermediate was conveniently acylated with varions acyl chlorides to yield several biologically active componnds of structure type 5. While this synthetic approach does access intermediate 4 in relatively few synthetic transformations for stractnre activity relationship studies, this route is seemingly nnattractive for preparative scale requiring stoichiometric amounts of potentially toxic metals that are generally difficult to remove and present costly purification problems at the end of the synthesis. 

Sometimes it is useful to be able to remove a protecting group by photolysis. 2-Nitrobenzyl carbamates meet this requirement. The photoexcited nitro group abstracts a hydrogen from the benzylic position, which is then converted to a a-hydroxybenzyl carbamate that readily hydrolyzes232... 

A molecular dissection of the alkaloid vasicine (52) ultimately resulted in the expectorant and mucolytic agent bromhexine (54). The synthesis starts with displacement of halogen on 2-nitrobenzyl-bromide (53) by N-methyl cyclohexylamine, followed by Raney nickel and hydrazine reduction of the nitro group. Bromination in acetic acid then affords bromhexine. 

Following an explosion dining drying of 2-nitrobenzyl bromide, the thermal stability of all six isomeric nitrobenzyl halides was investigated by TGA, DSC and ARC techniques. All the halides decomposed exothermally with abundant gas evolution, and the 2-nitro chloride is less thermally stable than the 3- or 4-isomers. See 2-Nitrobenzyl bromide... 

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