P-Cyanobenzyl bromide

Haloacetonitrile and p-cyanobenzyl bromide react similarly, leading to a,j8-unsaturated nitriles accompanied by minor amounts of the alcohols. 

Irradiation of NADH model compounds in the presence of benzyl bromide or p-cyanobenzyl bromide in acetonitrile brings about reduction of the benzyl halides to the corresponding toluene compounds114. Like the S l substitution reaction, this photoreduction also occurs via an electron-transfer chain mechanism. Unlike in that case, though, here an electron transfer from the excited state of the NADH compound is solely responsible for the initiation step. In the propagation, the benzyl radical produced by C—Br bond cleavage in the radical anion abstracts hydrogen from the NADH compound. This yields a radical intermediate, from which electron transfer to benzyl bromide occurs readily (equations 39-42). 

One reaction starting with p-cyanobenzyl bromide is shown later in the text along with the experimental details. 

The p-cyanobenzyl ether, prepared from an alcohol and the benzyl bromide in the presence of sodium, hydride (74% yield), can be cleaved by electrolytic reduction (—2.1 V, 71% yield). It is stable to electrolytic removal ( — 1.4 V) of a tritylone ether [i.e., 9-(9-phenyl-10-oxo)anthiyl ether]. ... 

II, 2.4]-triazin-3(2/y)-one (151, R = Me, R = H) (70JHCI23I). Similarly, 150 (R = Me) reacts with a-cyanobenzyl p-toluene sulfonate lPhCH(CN)OTS] or a-cyanobenzyl bromide PhCH(CN)Br] to afford 151 (R = Me, R = Ph) (7IJHC62I). Structure 151 was proved by its reduction with diborane to 152, which was also obtained by an independent synthesis involving the reaction of 153 with thionyl chloride followed by base-catalyzed cyclization (70JHCI231 71JHC621). To ascertain whether the methyl group at the I-position in 150 (R = Me) influences the direction of cyclization, the thione 150 (R = H) was allowed to condense with a-cyanobenzyl-p-toluene sulfonate and ethyl a-bromophenylacetate. In both cases 151 (R = H, R = Ph) was obtained. Compound 150, however, on reaction with 1,2-dibromoethane, furnished another bicyclic system (154). The difference in the behavior of 150 toward dibromoethane and other reagents such as ethyl bromoacetate and a-cyanobenzyl p-toluene... 

Prisms. M.p. 147°. SoL EtgO, MegCO. Spar, sol. Hgroin. InsoL HgO Nitrile see o-Cyanobenzyl bromide. 

G. Synthesis of m(-4-Phenylbutyl)bemamidine p-Toluenesvlfonate (3S). To a solution of 0.15 mmole of m-oyanobenzyl bromide (48) (Aldrich) in 150 ml of xylene is added a solution of 0.15 mmole of tri-phenylphosphine (40) (Aldrich) in 150 ml of xylene. The mixture is stirred at reflux for 1 hr and then chilled. The product, w-cyanobenzyl-... 

H. Synthesis of m-Styrylbemamidine p-Toluenesvlfonate 31) and m-Phenylethylbenzamidine p-Toluenesulfonate 82). By a procedure similar to that for compound 52, equal molar amounts of m-cyanobenzyl-triphenylphosphonium bromide 50) and benzaldehyde 54) are allowed to react with a slight excess of sodium methoxide in methanol. The resulting 2-(3-cyanophenyl) styrene is used directly in the Pinner reaction to yield compound 31. 

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