Benzo-nitrile

Reduction of nitriles—Aceto-nitrile—n-Propio-nitrile. [Aromatic nitriles—Benzo-nitrild —Benzyl-cyanide.].46-47... 

Hydrolysis of p-tolunitrile to p-toluic acid. Boil a mixture of 5 g. of p-tolunitrile, 80 ml. of 10 per cent, aqueous sodium hydroxide solution and 15 ml. of alcohol under a reflux condenser. (The alcohol is added to prevent the nitrile, which volatUises in the steam, from crystalhsing in the condenser it also increases the speed of hydrolysis. The alcohol may be omitted in the hydrolysis of nitriles which are hquid at the ordinary temperature, e.g., benzo-nitrUe.) The solution becomes clear after heating for about 1 hour, but continue the boiling for a total period of 1 - 5 hours to ensure complete hydrolysis. Detach the condenser and boil the solution for a few minutes in the open flask to remove dissolved ammonia and incidentally some of the alcohol CAUTION /). Cool, and add concentrated hydrochloric acid until precipitation of the p-toluic acid is complete. When cold, filter off the p-toluic acid with suction and wash with a little cold water. Recrystallise from a mixture of equal volumes of water and alcohol (methylated spirit) or from benzene. The yield of p-toluic acid, m.p. 178°, is 5-5 g. 

Cyclocondensation of 2-iminopiperidine hydrochloride with an E Z isomeric mixture of ethyl 2-cyano-3-methylsulfanyl-3-( 1,2,4,5-tetrahydro-3/f-benzo[r/ azepin-3-yl)acrylate in DMF in the presence of DBU at 100°C gave 2-substituted 6,7,8,9-tetrahydro-4//-pyrido[l, 2-n]pyrimidine-3-carbo-nitrile (01EUP1074549). 

Chloro-2-fluoro-5-sulfamoyl benzo-nitrile Azosemide... 

Dibenz[c,/][1,2]oxazcpine-ll-carbonitrile isomerizes to the TV-oxide acridine-9-carbonitrile 10-oxide on heating in aprotic solvents. Attempted chromatography on silica gel or alumina columns gave a mixture of the oxepino[2,3-6]quinolinecarbonitrile 2, the oxoazepinoindolecarbo-nitrile 3 and the benzo[c]-2-aza-l,6-oxa[10]annulenecarbonitrile 4. Only these types of compounds were isolated when 2,7-dimethylacridine 10-oxide was irradiated.6... 

By introducing reasonable values (about 2 for nitrogen, 4 for oxygen) for the electron affinity parameter relative to carbon, 8, and for the induced electron affinity for adjacent atoms (32/8i = Vio), we have shown that the calculated permanent charge distributions for pyridine, toluene, phenyltrimethylammonium ion, nitrobenzene, benzoic acid, benzaldehyde, acetophenone, benzo-nitrile, furan, thiophene, pyrrole, aniline, and phenol can be satisfactorily correlated qualitatively with the observed positions and rates of substitution. For naphthalene and the halogen benzenes this calculation does not lead to results... 

Hydrolysis of benzonitrile to benzoic acid. Boil 5 1 g. (5 ml.) of benzo-nitrile and 80 ml. of 10 per cent, sodium hydroxide solution in a 250 ml. round-bottomed flask fitted with a reflux water condenser until the condensed liquid contains no oily drops (about 45 minutes). Remove the condenser, and boil the solution in an open flask for a few minutes to remove free ammonia. Cool the liquid, and add concentrated hydrochloric acid, cautiously with shaking, ontil precipitation of benzoic acid is complete. Cool, filter the benzoic acid with suction, and wash with cold water dry upon filter paper in the air. The benzoic acid (5-8 g.) thus obtained should be pure (m.p. 121°). Recrystal-lise a small quantity from hot water and redetermine the m.p. 

Five grams of potassium hydroxide (85% KOH) is dissolved in 100 ml. of Methyl Cellosolve (Note 1) in a 500-ml. flask (Note 2) fitted with a mechanical stirrer, reflux condenser, and a heating mantle. Dicyandiamide (50.4 g. 0.6 mole) (Note 3) and benzo-nitrile (50 g. 0.485 mole) are added, and the mixture is stirred and heated. A solution is formed, and, when the temperature reaches 90-110°, an exothermic reaction begins and the product separates as a finely divided white solid. The vigor of the reaction is kept under control by the refluxing of the solvent (Note 4). 

There are a few communications concerning cycloadditions of nitrile oxides to unsaturated oxa and aza cage systems. Benzo- and mesitonitrile oxides RCNO give, with five substituted 7-oxanorbomenes 106, mixtures of the corresponding exo-adducts 107 and 108 in nearly quantitative yields. No traces of compounds resulting from the endo-face attack was detected (274). Substituents at positions 5 and 6 of 106 render the process highly regioselective. 

Mesitonitrile oxide, but not benzonitrile oxide, adds to aza-analogs of phenan-threne, viz., benzo[/z]quinoline, 1,10-, 1,7-, and 4,7-phenanthrolines to give low yields of mono-cycloadducts at the C(5)=C(6> bond. Only 4,7-phenanthroline gave minor products, of which one the bisadduct 167 was isolated in approximately 7% yield. Phenanthridine reacts with two nitrile oxides but affords phenanthridin-6-one rather than a cyclo-adduct (336). 

Benzo-flw-triazine tri-N-oxides 384 (R = H, Me R1 = mesityl, 2,6-ClC6H3) are formed from the reaction of nitrile oxides R CNO with benzofuroxans 385. The structure of 384 (R = Me, R1 = mesityl) has been confirmed by X-ray crystal structure analysis (431). 

Optically active 3-arylisoxazoline-5-carboxylic acid derivatives 403 or 404 have been, prepared by the reaction of (S)- or (/ )-3-acryloyl-4-benzyl-5,5-dimethyloxazolidin-2-one (405 or 406) with nitrile oxides, obtained from benzo-hydroximoyl chloride and its substituted derivatives in the presence of a catalytic amount of metal salt, for example, Yb(OTf)3 (445). This procedure improves the diastereoselectivity of compounds 403 or 404, which are industrially useful as intermediates for various drugs and agrochemicals. It also enables the amount... 

A combination of bromide ions and methyl octyl sulphide is able to oxidise secondary alcohols at the potential necessary to fonn bromine. Conversion of the alcohol to the ketone follows the Scheme 8.2 and uses an undivided cell with benzo-nitrile as the solvent containing 2,6-lutidine as base and tetraethylamnionium bromide. The reaction occurs using a platinum anode at 1.1 V vs-, see [28], Thio-anisole alone, in absence of bromide, will function as a catalyst for the oxidation of secondary alcohols but in these cases a more positive anode potential of 1.5 V vs. see is needed to oxidise the thioether [29]. 

Dihydro-4H-benzo[/]pyrrolo[l,2-fl][l,4]diazepin-4-one 220 is a product of reductive cyclizations of ester nitrile 219a (R = COOMe, = CN), while amido... 

Benzofurazans are thermally more stable but can be cleaved photolytically. For example, benzo-furazan itself in benzene affords cyanoisocyanate (17) and azepine (18), the latter being formed by reaction of the solvent with the putative intermediate acylnitrene (19) (Scheme 5) further supporting evidence for the proposed pathway is provided by trapping the nitrile oxide precursor with dimethyl acetylenedicarboxylate and isolation of the methylurethane derivative of the isocyanate <75JOC2880>. Photolysis of diphenylfurazan yields benzonitrile, diphenylfuroxan and 3,5-diphenyl-1,2,4-oxadiazole. 

The second class of benzo-fused heterocycles accessible from benzofuroxans are benzimidazole oxides. In this case only one carbon from the co-reactant is incorporated in the product. With primary nitroalkanes 2-substituted l-hydroxybenzimidazole-3-oxides (46) are formed via displacement of nitrite, and / -sulfones behave similarly. The nitrile group of a-cyanoacetamides is likewise eliminated to alford 2-amide derivatives (46 R = CONRjX and the corresponding esters are formed in addition to the expected quinoxaline dioxides from acetoacetate esters. Under similar conditions secondary nitroalkyl compounds afford 2,2-disubstituted 2//-benzimidazole-1,3-dioxides (47). Benzimidazoles can also result from reaction of benzofuroxans with phosphorus ylides <86T3631>, nitrones (85H(23)1625>, and diazo compounds <75TL3577>. 

The same compound has been prepared in poor yield by treating benzo-nitrile oxide with dicyandiamide (J9) (see p. 826). 

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