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Benzonitrile, reaction with base

Another example of the remarkable reactivity of Mg actuated by our procedure is its reaction with nitriles. In this respect, the Mg resembles an alkali metal more than an alkaline earth. Benzonitrile reacts with Mg overnight, in refluxing DME, to give 2,4,6-triphenyl-l,3,5-triazine and 2,4,5-triphenylimidazole in 26 and 27% yield, respectively, based on magnesium. Jhe imidazole was shown to arise, at least in part, from the action of Mg on the triazine. The trimerization of aromatic nitriles to give symmetrical triazines is not unknown, but generally the reactions are... [Pg.239]

This number is based on the observation that in the reaction with SO], k(observed) for formation of optical density at 340 nm (where the OH adduct of benzonitrile absorbs) is proportional to [benzonitrile] up to the saturation limit ( a 20 mM, k(observed) = 5 x 10 s" ), as shown by 248 nm laser experiments... [Pg.145]

A variety of substituted 3-aminobenzo[6]thiophenes have been obtained by ring closure reactions of nitriles (equation 57). Various o -cyanophenylthioacetyl derivatives, when treated with base, yield the 3-amino derivatives (Section 3.15.2.2.3). The benzonitriles may be obtained by displacement of the o-nitro group from o -nitrobenzonitriles (74JOC3440). 2-Arylthio-l-chloroenamines are cyclized to 3 -dialkylaminobenzo[6]thiophenes in the presence of Lewis acid catalysts (equation 58). The 1 -chloroenamines may be prepared from t-amides or ynamines <8lH(15)l 179>. [Pg.925]

Benzonitrile oxide (C in Figure 15.44) is an isolable 1,3-dipole. It can be generated from benzaldoxime and anNaOH/Cl2 solution. Under these reaction conditions the oxime/nitroso anion (A B) is initially formed and chlorine disproportionates into Cl—O and chloride. An SN reaction of the negatively charged C atom of the anion A B at the Cl atom of Cl— O or of Cl—O—H affords the oc-chlorinated nitroso compound E, which tautomerizes to the hydroxamic acid chloride D. From that species, the nitrile oxide C is generated via a base mediated 1,3-elimination. Isoxazoles are formed in the reactions of C with alkynes (Figure 15.44), while isoxazolines would be formed in its reactions with alkenes. [Pg.681]

In a variation on this theme MgioAl2(OH)24C03 has been shown to catalyze the oxidation of a variety of olefins-linear and cyclic-and unsaturated alcohols and ketones with H2O2 in the presence of benzonitrile [60]. The reaction involves in situ formation of the Payne reagent [61], PhC(OOH)=NH, by base-catalyzed reaction of H2O2 with benzonitrile (Eq. 5). Reaction with the olefin then affords the epoxide and one equivalent of benzamide (Eq. 6). [Pg.480]

B.iv. Nitrile Enolates. Nitrile enolates are formed by reaction of a nitrile with LDA or another suitable base. Both alkylation 30 and condensation reactions with aldehydes 3 or ketones are known. 32 in addition to alkyl halides and carbonyl derivatives, condensation can occur with another nitrile. The base-catalyzed condensation of two nitriles to give a cyano-ketone, via an intermediate cyano enolate, is known as the Thorpe reaction. 33.109e Reaction of butanenitrile with sodium ethoxide gave a nitrile enolate, which reacted with a second molecule of butanenitrile at the electrophilic cyano carbon to give 206. Hydrolysis gave an intermediate imine-nitrile (207), which is in equilibrium with the enamine form (208, sec. 9.6.A). Hydrolysis led to the final product of the Thorpe reaction, an a-cyano ketone, 209. 33 Mixed condensations are possible when LDA and kinetic conditions are used to generate the a-lithionitrile (a mixed Thorpe reaction). When pentanenitrile was treated with LDA and condensed with benzonitrile, 2-cyano-l-phenyl-1-pentanone was the isolated product after acid hydrolysis. Nitrile enolates can also be alkylated with a variety of alkyl halides. 34... [Pg.752]

Nitriles may be hydrolyzed to carboxylic acids with the use of base (or acid). With base, ammonia is also released. Consequently, when NaOH is added to benzonitrile, ammonia is released and can be detected with litmus paper. Nitrobenzene will not give the reaction. [Pg.809]

The synthesis of N-benzylphthalimidine by reaction of ben2onitrile [688] with carbon monoxide or synthesis gas in the presence of cobalt carbonyls may be regarded as a special case of the reaction with Schiff bases. It is known that nitriles can give Schiff bases as intermediates on hydrogenation [689]. From the products obtained in the carbonylation of nitriles, and from the fact that higher yields are obtained with synthesis gas than with pure carbon monoxide [677], as well as from the observation that the best yields are obtained when 1 mole of benzylamine is added per mole of benzonitrile [677], it is very probable that the formation of the phthal-imidine in this case again proceeds via the Schiff base. [Pg.161]

Beckmann reactions of the oxime of thioisochroman-4-one proceed normally, except with sulphury 1 chloride, when ring-opening occurs, and a benzonitrile derivative is obtained. The sulphonium salt (69) forms the stabilized ylide (70) on treatment with base. Methylation of the ylide occurs... [Pg.535]

Uses. The principal use of adiponitrile is for hydrogenation to hexamethylene diamine leading to nylon-6,6. However, as a result of BASE s new adiponitrile-to-caprolactam process, a significant fraction of ADN produced may find its way into nylon-6 production. Adipoquanamine, which is prepared by the reaction of adiponitrile with dicyandiamide [461-58-5] (cyanoguanidine), may have uses in melamine—urea amino resins (qv) (see "Benzonitrile, Uses"). Its typical Hquid nitrile properties suggest its use as an extractant for aromatic hydrocarbons. [Pg.221]

The raw material has to be washed to remove impurities. Diluted sodium hydroxide allows the removal of phenols and benzonitrile, and diluted sulphuric acid reacts with pyridine bases. The resulting material is distilled to concentrate the unsaturated compounds (raw feedstock for coumarone-indene resin production), and separate and recover interesting non-polymerizable compounds (naphthalene, benzene, toluene, xylenes). Once the unsaturated compounds are distilled, they are treated with small amounts of sulphuric acid to improve their colour activated carbons or clays can be also used. The resulting material is subjected to polymerization. It is important to avoid long storage time of the feedstock because oxidation processes can easily occur, affecting the polymerization reaction and the colour of the coumarone-indene resins. [Pg.604]

The azuleno[l, 8-rc/]azepine 35 is formed as a byproduct from the reaction of excess benzonitrile with 7-isopropyl-l,4-dimethylazulene (guaiazulene, 34) in the presence of a strong base.111 The mode of formation of this unexpected fully conjugated 14jt system has been discussed. [Pg.123]

Similarly, reactions which are substantially enhanced by the use of PTC can be carried out even with reduced use of PTC with substantial enhanced rates of reaction as has been demonstrated by Sivakumar and Pandit (2000) in the case of conversion of benzamide to benzonitrile. In the case of A-alkylation of diphenylamine with benzyl bromide, in the presence of KOH as the anion source and PEG methyl ether as the PTC, some improvement in the rate has been observed. (Cains et al., 1998). Metal catalysed hydrogenations, such as those based on Ni, Pd/C, and Ru/C also benefit from ultra-sound. [Pg.165]

The formation of a DPP molecule was first reported in 1974 as a minor product in low yield from the reaction of benzonitrile with ethyl bro-moacetate and zinc. A fascinating study by research chemists at Ciba Geigy into the mechanistic pathways involved in the formation of the molecules led to the development of an efficient one-pot synthetic procedure to yield DPP pigments from readily available starting materials, as illustrated in Scheme 4.10. The reaction involves the treatment of diethyl succinate (1 mol) with an aromatic cyanide (2 mol) in the presence of a strong base. The reaction proceeds through the intermediate 88, which may be isolated and used to synthesise unsymmetrical derivatives. [Pg.91]

The reaction of the ( -configured Schiff base 315 with benzonitrile oxide gave the 4,5-dihydro-l,2,4-oxadiazole 316 as a single diastereomer (Equation 59) <1999AXC650>. [Pg.292]

DPP pigments are synthesized by reacting succinic ester with benzonitriles in the presence of alcoholate in the corresponding alcohol for base catalysis. Originally starting from sodium methylate/methanol an important step toward a significantly improved yield was achieved by reaction of succinic tert.-alkylester in sodium tert.-alkylalcoholate/tert.-alkylalcohol. [Pg.488]


See other pages where Benzonitrile, reaction with base is mentioned: [Pg.640]    [Pg.95]    [Pg.640]    [Pg.146]    [Pg.35]    [Pg.231]    [Pg.784]    [Pg.664]    [Pg.631]    [Pg.664]    [Pg.211]    [Pg.16]    [Pg.406]    [Pg.446]    [Pg.664]    [Pg.9]    [Pg.618]    [Pg.676]    [Pg.204]    [Pg.171]    [Pg.224]    [Pg.71]    [Pg.240]    [Pg.212]    [Pg.413]    [Pg.92]    [Pg.176]    [Pg.109]    [Pg.327]    [Pg.112]    [Pg.137]   
See also in sourсe #XX -- [ Pg.530 ]

See also in sourсe #XX -- [ Pg.530 ]




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