Nitrobenzyl chloride

Nitrobenzyl chloride obtained from the Eastman Kodak Company was used. 

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. 

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... 

A variation of the Madelung cyclization involves installing a functional group at the o-methyl group which can facilitate cyclization. For example, a triphenylphosphonio substituent converts the reaction into an intramolecular Wittig condensation. The required phosphonium salts can be prepared by starting with o-nitrobenzyl chloride or bromide[9]. The method has been applied to preparation of 2-alkyl and 2-arylindoles as well as to several 2-alkenylindoles. Tabic 3.2 provides examples. 

These have been reviewed in an earlier volume. -Nitro-benzaldehyde has also been prepared in 32% yield by heating /)-nitrobenzyl chloride with potassium fer/-butylperoxide. The... 

Example 4.4. Using data in Tables 4.5 and 4,6, ealculate how much faster p-bromobenzyl chloride will solvolyze in water than will /i-nitrobenzyl chloride. 

A study of alkylations with a group of substituted benzyl halides and a range of Friedel-Crafts catalysts has provided insight into the trends in selectivity and orientation that accompany changes in both the alkyl group and the catalysts. There is a marked increase in substrate selectivity on going from / -nitrobenzyl chloride to /i-methoxybenzyl chloride. For example, with titanium tetrachloride as the catalyst, Aitoi Abenz increases from 2.5 to 97. This increase in substrate selectivity is accompanied by an increasing preference for para substitution. With /i-nitrobenzyl chloride, the ortho para ratio is 2 1 (the... 

A mechanism of this type permits substitution of certain aromatic and ahphatic nitro compounds by a variety of nucleophiles. These reactions were discovered as the result of efforts to explain the mechanistic basis for high-yield carbon alkylation of the 2-nitropropane anion by p-nitrobenzyl chloride. p-Nitrobenzyl bromide and iodide and benzyl halides that do not contain a nitro substituent give mainly the unstable oxygen alkylation product with this ambident anion ... 

The absolute rate of dissociation of the radical anion of /i-nitrobenzyl chloride has been measured as 4 x 10 s . The w-nitro isomer does not undergo a corresponding reaction. This is because the meta nitro group provides no resonance stabilization of the benzylic radical. 

The American authors suggested (X) or (XI), already considered by Spath and Nikawitz for vasicine, and support for a formula of type (XI) was provided by Spath, Kuffner and Platzer, who, by condensing o-nitrobenzyl chloride with methyl y-aminobutyrate to o-nitrobenzyl-pyrrolidone (XII), reduction of this to the amino-compound (XII NOa —> NHj) and ring-closure in presence of phosphoryl chloride obtained the base d -pegene (XIII), m.p. 99-100°, identical with the product formed by the reduction of deoxychloropeganine. The same substance... 

The ability of a nltro group in the substrate to bring about electron-transfer free radical chain nucleophilic subsdnidon fSpj li at a saniratedcarbon atom is well documented. Such electron transfer reacdons are one of the characterisdc feanires of nltro compounds. Komblum and Russell have established ihe Spj l reaction independently the details of the early history have been well reviewed by them. The reacdon of -nitrobenzyl chloride v/ith a salt of nitro ilkane is in sharp contrast to the general behavior of the ilkyladon of the carbanions derived from nitro ilkanes here, carbon ilkyladon is predominant. The carbon ilkyladon process proceeds via a chain reacdon involving anion radicals and free radicals, as shovmin Eq. 5.24 and Scheme 5.4 fSpj l reacdoni. 

Diethyl sodium phthalimidomalonate (Barger and Weichselbaum, Organic Syntheses, 1943, Coll. Vol. II, 3B4) (6.52 g) was dissolved in boiling methyl ethyl ketone (BO ml) and a solution of p-nitrobenzyl chloride (3.44 g 1.0 mol) in the same solvent (20 ml) was added. Sodium iodide (ca 0.5 g) dissolved in hot methyl ethyl ketone (10 ml) was introduced, and produced an immediate precipitation. The mixture was refluxed for 1.5 hours, cooled, filtered, evaporated under vacuum and the residual gum crystallized from ethanol. The di-ethyl-p-nitrobenzyl-phthalimidomalonate formed colorless prisms (B8%), MP 103° to 105°C, sharpening to 104° to 105°C on recrystallizing from ethanol. 

Nitrobenzaldehyde has been prepared from />-nitrotoluene by treatment with isoamyl nitrite in the presence of sodium methylate,1 by oxidation with chromyl chloride,2 cerium dioxide,3 or chromium trioxide in the presence of acetic anhydride.4 It can also be prepared by the oxidation of -nitrobenzyl chloride,5 7>-nitrobenzyl alcohol,6 or the esters of -nitrocinnamic acid.7... 

Third-order rate coefficients were determined for reaction of some aromatics with 3,4-dichlorobenzyl chloride at 25 °C as follows chlorobenzene, 0.745 x 10 3 benzene, 1.58 x 10-3 toluene 2.60 x 10—3 m-xylene, 3.30 x 10-3 and these show the unselective nature of the reaction. With 4-nitrobenzyl chloride, benzene gives a third-order rate coefficient of 4.78 x 10 6, which diminishes to 2.4 and 1.9 x 10-6 as the benzene composition of the solvent was increased to 50 and 83 vol. %, respectively. 

Since nitrobenzene is a much stronger base than alkyl halides, the concentration of RCI.AICI3 will be small and hence k i will be large and, therefore, much greater than k 2. Equation (180), therefore, reduces to a third-order expression which includes the equilibrium constant k jk i) of the first step and this accounts for the lower rates with 4-nitrobenzyl chloride since it is a poorer base than the 3,4-dichloro compound. 

Horton, H. R. Young, G. 2-Acetoxy-5-nitrobenzyl chloride. A reagent designed to introduce a reporter group near the active site of chymotrypsin. Biochem. Biophys. Acta. 1969, 94, 272-278. 

When a mixture of benzene (B) and benzyl chloride (C) are reacted with nitric acid (A) in acetic anhydride solution, the products are nitrobenzene (NB) and nitrobenzyl chloride (NC). 

Run Initial hno3 (kmoles/m3) Nitrobenzene concentration after complete reaction (kmoles/m3) Nitrobenzyl chloride concentration after complete reaction (kmoles/m3)... 

From the reaction stoichiometry is numerically equal to the nitrobenzene concentration and is equal to the nitrobenzyl chloride concentration. Since B0 and C0 are each unity, equation D may be written as... 

A mixture of 250 g. (1.46 moles) of />-nitrobenzyl chloride, 225 g. (2.74 moles) of fused sodium acetate, and 375 g. (6.25 moles) of glacial acetic acid is refluxed for 8 to 10 hours in a 2-1. flask heated by an oil bath, the temperature of which is maintained at 160-170° (Note 1). After this time the bath is allowed to cool to about 125°, and the acetic acid is removed by distillation under reduced pressure. Care must be taken not to reduce the pressure too rapidly in the early stages of the distillation. As the distillation slows down, the pressure is further reduced until it reaches 50 mm. or lower, and the temperature is slowly raised to 160°. From 2.5 to 3 hours is required for the complete removal of the acetic acid. About 500 ml. of water is added, and the hard cake is broken up with a stirring rod (Note 2). 

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