Reduction benzyl chloride

Diphenylmethane has been prepared with aluminum chloride as a catalyst from methylene chloride and benzene, from chloroform and benzene as a by-product in the preparation of triphenylmethane, and from benzyl chloride and benzene. It has been prepared by the reduction of benzophenone with hydriodic acid and phosphorus, or with sodium and alcohol. It has also been made by heating a solution of benzyl chloride in benzene with zinc dust, or with zinc chloride. The above method is only a slight modification of the original method of Hirst and Cohen. ... 

The stereoselective reactions in Scheme 2.10 include one example that is completely stereoselective (entry 3), one that is highly stereoselective (entry 6), and others in which the stereoselectivity is modest to low (entries 1,2,4, 5, and 7). The addition of formic acid to norbomene (entry 3) produces only the exo ester. Reduction of 4-r-butylcyclohexanone (entry 6) is typical of the reduction of unhindered cyclohexanones in that the major diastereomer produced has an equatorial hydroxyl group. Certain other reducing agents, particularly sterically bulky ones, exhibit the opposite stereoselectivity and favor the formation of the diastereomer having an axial hydroxyl groi. The alkylation of 4-t-butylpiperidine with benzyl chloride (entry 7) provides only a slight excess of one diastereomer over the other. 

Reduction of phenylacetone in the presence of methylamine rather than ammonia gives methamphetamine (53), an agent similar in action to the primary amine. Alkylation of 53 with benzyl chloride affords the analog, benzphetamine (54). ... 

The p-chloro analog of phentermine has much the same activity as the parent compound, with perhaps a somewhat decreased activity on the central nervous system. Alkylation of p-chloro-benzyl chloride with the carbanion obtained from treatment of 2-nitropropane with strong base affords the compound containing the required carbon skeleton (74). Catalytic reduction of the nitro group yields chlorphentermine (75). ... 

The key intermediate 21 is in principle accessible in any of several ways. Thus reaction of thiophenecarbox-aldehyde with amninoacetal would lead to the Schiff base 20 treatment with acid would result in formation of the fused thiophene-pyridine ring (21). Alkylation of that intermediate with benzyl chloride gives the corresponding ternary imini urn salt 23. Treatment with sodium borohydride leads to reduction of the quinolinium ring and thus formation of ticlopidine (24). ... 

Benzylacetophenone has been prepared by the reduction of benzalacetophenone with zinc and acetic acid1 and catalytic-ally with palladium and hydrogen 2 by the reduction of /3-duplo-benzylidene acetophenone monosulfide 3 by the oxidation of the corresponding car bind with chromic acid 4 by the hydrolysis of ethyl benzyl benzoylacetate 5 from acetophenone and benzyl chloride by the action of sodamide 6 and from benzoic and hydrocinnamic adds using as catalysts manganese oxide 7 and ferric oxide.8... 

Si-H containing functional initiators have been obtained by reduction with LAH of the corresponding Si-Cl containing compounds. Conditions have been developed under which the benzylic chloride remains unchanged while the Si-Cl bond is converted to Si-H (for experimental details see Sect. H.C.). The initiators obtained are shown in Table 1. 

Attempts have been made to trap the intermediate radical with a monomer, particularly in the reduction of benzyl chloride by Cr(II) to benzylchromium ion (and ultimately to toluene and dibenzyl). The results were ambiguous, however, as benzylchromium ion itself reacts with butadiene and acrylonitrile. This reduction shows second-order kinetics with E — 14.6 kcal.mole and = 14.3 eu. The rate coefficients for benzyl chloride, bromide and iodide follow the expected sequence ... 

Friedel-Crafts alkylations are among the most important reactions in organic synthesis. Solid acid catalysts have advantages in ease of product recovery, reduced waste streams, and reduction in corrosion and toxicity. In the past, people have used (pillared) clays (18), heteropolyacids (19) and zeohtes (20) for Friedel-Craft alkylations, with mixed success. Problems included poor catalyst stabihty and low activity. Benzylation of benzene using benzyl chloride is interesting for the preparation of substitutes of polychlorobenzene in the apphcation of dielectrics. The performance of Si-TUD-1 with different heteroatoms (Fe, Ga, Sn and Ti) was evaluated, and different levels of Fe inside Si-TUD-1 (denoted Fei, Fe2, Fes and Feio) were evaluated (21). The synthesis procedure of these materials was described in detail elsewhere (22). 

Reaction of allyl nalides with the iron powders is rapid and exothermic and leads to near quantitative yields of the self-coupled product 1,5-hexadiene. Similarly, reaction of benzyl chloride with the iron powders at room temperature yields bibenzyl in 60-70% yields along with 20-25% of toluene. In contrast, reaction of aryl halides with the iron powders leads to reductive cleavage rather than self-coupling. Similarly, reaction of 1-bromoheptane with the iron powder in THF for three hours at room... 

Cobaloxime(I) generated by the electrochemical reductions of cobaloxime(III), the most simple model of vitamin Bi2, has been shown to catalyze radical cyclization of bromoacetals.307 Cobalt(I) species electrogenerated from [ConTPP] also catalyze the reductive cleavage of alkyl halides. This catalyst is much less stable than vitamin Bi2 derivatives.296 It has, however, been applied in the carboxylation of benzyl chloride and butyl halides with C02.308 Heterogeneous catalysis of organohalides reduction has also been studied at cobalt porphyrin-film modified electrodes,275,3 9-311 which have potential application in the electrochemical sensing of pollutants. 

Alkyl iodides, benzyl chlorides, benzyl bromides, and adamantyl bromides and iodides undergo reduction with triethylsilane/palladium chloride.195 The reduction of a /3-chloro ether occurs in excellent yield with this system (Eq. 56).195... 

Reduction to Halocarbons. The best conditions for the reductive chlorination of ketones use the reagent combination Me2ClSiH/In(OH)3 (Eq. 241).331 Examples include conversions of aryl ketones to benzyl chlorides, ethynyl ketones to propargyl chlorides, and alkyl ketones to alkyl chlorides (Eq. 242).331 Addition of lithium iodide to the reaction mixture yields the corresponding iodide product. The combination of TMDO/I2 reductively iodinates aryl ketones and aldehydes in good yields (Eq. 243).357... 

Halocarbons, ketone-alcohol reduction, 84 Halogenation, 4-methylbenzyl chloride [reductive halogenation of aldehyde to benzyl chloride], 124 Hemiacetals, reduction of, 97-99 Hemiaminals, reduction of, 99-100 Hemiketals, reduction of, 97-99 Heptene derivatives, alkene to alkane reductions, disubstituted alkenes, 36-38... 

The procedure described is essentially that of Ballard and Dehn.1 Stilbene has also been prepared by reduction of desoxy-benzoin,20 benzaldehyde,23 and benzil 2o-2c by dehydrogenation of ethyl benzene,30 toluene,30- 33- 3, and bibenzyl 33-3alkaline reduction of phenylnitromethane,40 phenylnitroacetonitrile,40 and desoxybenzoin 43 by distillation of benzyl sulfone,50 benzyl sulfide,60-63 calcium cinnamate,5 cinnamic acid,5d phenyl cinna-mate,6e-6/ and diphenyl fumarate ie by dehydrohalogenation of a,a -dichlorobibenzyl60 and benzyl chloride 63 by dehalogenation of a,a,c/,a -tetrachlorobibenzyl70 and benzal chloride 73 by the coupling of cinnamic acid and phenyldiazonium chloride 8 by de-... 

The facile homogeneous catalysed reduction of acid chlorides to alcohols has many advantages over reduction with sodium borohydride in hydroxylic solvents where rapid reaction of the acid chloride with the solvent can occur [10]. The procedure has been incorporated into a simple one-pot conversion of aroyl chlorides into the corresponding benzyl chlorides (Scheme 11.1) under liquidrliquid or solid-liquid two-phase conditions [11], The reduction of a limited number of aryl compounds was reported with ca. 70% overall yields, although poorer yields result from the reduction of 4-nitro-, 2-cyano- and 2,4-dichlorobenzoyl chlorides, and the reduction failed completely with terphthaloyl chloride and with its 2,3,5,6-tetrafluoro derivative [11]. 

Mechanistic aspects of the reduction of benzyl halides at mercury have been extensively investigated [35, 38]. From the reduction of benzyl iodide at platinum, Koch and coworkers [39] obtained toluene, bibenzyl, and hydrocinnamonitrile. Electrolysis of benzyl chloride in the presence of acyl chlorides can be used to synthesize alkyl benzyl ketones [40], whereas alcohols are formed by electrolysis of... 

Lund and coworkers [131] pioneered the use of aromatic anion radicals as mediators in a study of the catalytic reduction of bromobenzene by the electrogenerated anion radical of chrysene. Other early investigations involved the catalytic reduction of 1-bromo- and 1-chlorobutane by the anion radicals of trans-stilhene and anthracene [132], of 1-chlorohexane and 6-chloro-l-hexene by the naphthalene anion radical [133], and of 1-chlorooctane by the phenanthrene anion radical [134]. Simonet and coworkers [135] pointed out that a catalytically formed alkyl radical can react with an aromatic anion radical to form an alkylated aromatic hydrocarbon. Additional, comparatively recent work has centered on electron transfer between aromatic anion radicals and l,2-dichloro-l,2-diphenylethane [136], on reductive coupling of tert-butyl bromide with azobenzene, quinoxaline, and anthracene [137], and on the reactions of aromatic anion radicals with substituted benzyl chlorides [138], with... 

Cobalt(I) salen has been employed as a catalyst for the reduction of the following species benzal chloride [159] benzotrichloride [160] 1-bromobutane, 1-iodobutane, and 1,2-dibromobutane [161] iodoethane [162], benzyl chloride [163], and ethyl chloroacetate [164]. Rusling and coworkers have investigated the use of cobalt(I) salen, as well as vitamin Bi2s and cobalt(I) phthalocyanine, in both homogeneous phase and bicontin-uous microemulsions for the catalytic reduction of vicinal dibromides [165] and... 

Two methods were used to measure the chlorine leaving-group KIE for the 5n2 reduction of benzyl chloride to toluene by sodium borohydride in DMSO at 30 °C. One procedure involved the classical IRMS technique. The second method was a new technique in which the ratio of the chlorine isotopes was obtained by fast atom bombardment mass spectrometry on silver chloride recovered from the reaction. The KIE values found by the two methods were 1.007 and 1.008, respectively,... 

Barek et al. have reported on the determination of AT-nitroso compounds, azo compounds, heterocychcs, aromatic nitro compounds, heterocychc amines and even benzyl chloride using electrochemical methods such as voltammetry and polarog-raphy. The nitro and AT-nitroso compounds work particularly well in reductive mode [47, 48]. For appropriate analytes, adsorptive stripping voltammetry and anodic stripping voltammetry can give orders of magnitude lower detection hmits than are available from HPLC with electrochemical detection [48]. 

Reduction of alkyl and benzyl halides proceeds in two one-electron addition steps. The first detectable product is the alkyl or benzyl radical and this is reduced further to the carbanion. Some alkyl iodides show two polarographic waves corresponding to the two steps. Alkyl bromides show only one two-electron wave and alkyl chlorides are not reducible in the available potential window. Benzyl halides also show only one wave and benzyl chlorides are reducible in the available potential range. Reduction potentials measured in dimethylformamide are collected in... 

Reduction of a range of allyl and benzyl chlorides at a stainless steel cathode in dimethylformamide in the presence of carbonyl compounds and using a sacrificial anode of aluminium or zinc, leads to a Reformatsky-type reaction in 40-80 % yields. Allyl halide give products by reaction at both the a- and y-positions. Tetra-chioromethane and bromotrifluoromethane take part in similar reactions provided a... 

In an extension of this work, Schnider and his colleagues condensed the salt (36) with the Grignard reagent from p-methoxy-benzyl chloride. The product (40), on reduction (41) and cyclizar-tion, affords the methoxylated morphinan (41). Removal of the methyl ether affords the narcotic analgesic racemorphan (43). ... 

A still different scheme is used for the preparation of the benzimidazole buterizine (74). Alkylation of benzhydrylpiperazine with substituted benzyl chloride 70 gives the intermediate 7U Nucleophilic aromatic displacement on this compound by means of ethyl amine leads to reduction of the nitro group then gives the diamine T. Treatment of that with the orthoformate ester of pentanoic acid serves to form the imidazole ring. There is thus obtained the peripheral vasodilating agent buteri zi ne (74). ... 

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