O-Nitrobenzyl Bromide

Dicbloronitrobenzene o-Nitrobenzyl chloride m-Nitrobenzyl chloride p-Nitrobenzyl chloride o-Nitrobenzyl bromide m-Nitrobenzyl bromide p-Nitrobenzyl bromide o-Nitrobenzyl iodide m-Nitrobenzyl iodide p-Nitrobenzyl iodide o-Nitrobenzyl cyanide... 

Suction filtration is necessary. The filtration is conveniently carried out through a regular Buchner funnel connected through a rubber stopper to a 1-1. suction flask. Since o-nitrobenzyl bromide is a powerful lachrymator, the filtration should be carried out in a fume hood. 

Thermal stabilities of the six o-, m- and p-nitrobenzyl bromides and chlorides were studied comparatively by TGA, DSC and ARC techniques. In open sample containers, only o-nitrobenzyl bromide decomposed exothermally, but in sealed capsules all the compounds decomposed exothermally after melting, with abundant gas evolution. 

Nitrobenzyl halides are reduced in a 1 e-process to radical anions, which rapidly lose halide ion to form the neutral nitrobenzyl radical. The rates for this dissociation were calculated from cyclic voltammetry data to be k = 2,5 for m-nitrobenzyl chloride and k = 2 109 secfor o-nitrobenzyl bromide. The nitrobenzyl radicals predominantly dimerize (90%), whereas a small amount yields nitrotoluenes (< 10%) by hydrogen abstraction 4541. From a series of substituted benzyl bromides those with the more positive reduction potential form bibenzyl in 25—74% yield, whereas from the less easily reducible ones dibenzyl-mercury derivatives are obtained (50—60%) 485). Reduction of benzyl chloride at the plateau of the first wave yields dibenzylmercury 4 By reduction of diphenyliodonium hydroxide at -1,6 V 51% diphenylmercury is obtained 488 ... 

Pedro et al. reported the enantioselective synthesis of (,S )-3-hydroxy-3-phenyl-3,4-d i hydroquinol i n - 2 (1 /f)-o n c through an extension of their methodology for the diastereoselective benzylation of (.S )-mandelic acid <07S108>. The reaction commences with the benzylation of dioxolane 90 with substituted o-nitrobenzyl bromides 91 followed by the cyclization of adduct 92 resulting in enantiomerically pure dihydroquinolines 93 in good to high yields. 

The original o-nitrobenzyl bromide linker 1.19 (76) attached to aminomethyl PS resin has been used for both peptide and small organic molecule SPS. Cleavage by photolysis at 350 nm under anaerobic conditions gives carboxylic acids the insertion of an a-methyl allowed an easier cleavage (77). The linker 1.19 has also been prepared... 

Introduction of substituents into the aromatic ring makes the benzylic system prone to further deblocking methods. Thus, o-nitrobenzyl ethers, available from o-nitrobenzyl bromide, are cleaved photolyti-caiiyi38 and the mono- and di-methoxybenzyl groups (Mpm and Dmpm) are removable by oxidation... 

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