Carbonitriles Nitriles

A second practical route to AT-unsubstituted amides is by the controlled hydrolysis of nitriles, which can often be made (in the 5-position) by primary synthesis or (elsewhere) by displacement of an ammonio grouping. Thus 4,6-dimethylpyrimidine-2-carbonitrile (798 R = CN) in warm aqueous ammonia gives the amide (798 R = CONH2) in good yield... 

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... 

This synthetic process is applicable to the preparation of other aromatic nitriles from aldehydes. The submitters have used it to prepare 5-bromoindole-3-carbonitrile, 7-azaindole-3-carboni-trile, j)-chlorobenzonitrile, 3,4,5-trimethoxybenzonitrile, and p-N,N-dimethylaminobenzonitrile.9 There are several advantages to its use. They include (a) readily available and inexpensive reagents, (b) a simple, time-saving procedure, and (c) fair to good yields of nitrile obtained by a one-step method. 

The synthesis of pyrido[2,3-d]pyrimidin-7(8H)-ones has also been achieved by a microwave-assisted MCR [87-89] that is based on the Victory reaction of 6-oxotetrahydropyridine-3-carbonitrile 57, obtained by reaction of an Q ,/3-unsaturated ester 56 and malonitrile 47 (Z = CN). The one-pot cyclo condensation of 56, amidines 58 and methylene active nitriles 47, either malonitrile or ethyl cyanoacetate, at 100 °C for benzamidine or 140 °C for reactions with guanidine, in methanol in the presence of a catalytic amount of sodium methoxide gave 4-oxo-60 or 4-aminopyridopyrimidines 59, respectively, in only 10 min in a single-mode microwave reactor [87,88]... 

Yeom, S.-J., Kim, H.-J. and Oh, D.-K. (2007) Enantioselective production of 2,2-dimethylcyclopropane carboxylic acid from 2,2-dimethylcyclopropane carbonitrile using the nitrile hydratase and amidase of Rhodococcus erythropolis ATCC 25544. Enzyme and Microbial Technology, 41, 842-848. 

Cyclic nitriles are named by adding the suffix carbonitrile to the name of the ring system to which the -CN group is attached. 

In the presence of bis(acetylacetonato)nickel, a-dicarbonyl compounds readily add at the nitrile group of 4-R-substituted l,2,5-oxadiazole-3-carbonitriles 219 to form enaminofurazans 220. The adducts obtained from 4-amino-3-cyanofurazan underwent intramolecular cyclization upon heating with acetic acid in ethanol to give furazano[3,4- ]pyridine 221 derivatives in high yields (Scheme 51) <2001RCB1280>. 

Machiguchi, Nozoe and coworkers have very recently observed that in contrast to chemical reactivity of tropones, the tosylate of tropone oxime undergoes a facile ring-opening to 6-substituted (Z,Z,Z)-1,3,5-hexatriene nitriles on reaction with various nucleophiles305. For example, reaction of phenyl lithium results in the corresponding hexatriene carbonitrile (equation 183). 

Nitrile oxides, RNCO, are derivatives of fulminic acid (R = H). They can be named as fulmido-substituted parent molecules, but usually their names are derived from corresponding nitriles, for example, benzonitrile oxide, mesitonitrile oxide, thiophene-2-carbonitrile oxide. 

Evidently, stable nitrile oxides can be investigated by spectral and X-ray methods using ordinary procedures. As examples, X-ray diffraction studies of o-sulfamoylbenzonitrile oxides (20), 5-methyl-2-(methylsulfonyl)-3-thiophene-carbonitrile oxide (21), (),( >-diphenylacrylonitrile oxide (22), and (dimorpholino-phosphoryl) carbonitrile oxide (23) can be cited. It should be underlined that structures of the latter compounds differ from those of classical stable 0,0 -disubstituted arylcarbonitrile oxides and tert-alkylcarbonitrile oxides. Therefore, not only purely steric shielding of the CNO group but also electrostatic or donor-acceptor interactions between the atoms of the latter and adjacent polar substituents (21, 23) and also electron delocalization in it-systems (20, 22) enhance the stability of nitrile oxide. 

Chromone-3-carbonitrile oxide undergoes cycloaddition reactions with phenyl-and diphenylacetylenes to give isoxazoles 205 (R = H, Ph). The nitrile oxide is obtained from 3-formylchromone oxime by bromination and subsequent dehy-drobromination (175). 

A23-22-Oxo steroids 424 have been synthesized via 1,3-dipolar cycloaddition of steroidal nitrile oxides to low-molecular dipolarophiles. Cycloaddition of 2-propynyl bromide to 20-carbonitrile oxide, followed by hydrogenation of the isoxazole derivative, gives 22-enamino-24-keto steroid. The latter has then been converted into the target enones in several steps (465). 

In another approach (Scheme 92) enamino nitriles 249 serve as starting materials for pyrimidine syntheses. After transformation with triethyl orthoformate to 2-ethoxymethylenimino-3-carbonitriles (250), these are cyclized with semicarbazide to pyrano[2,3-d]pyrimidin-3-yl ureas (251). Dichlorotri-phenylphosphorane reacts in a second cyclization to give l,2,4-triazolo[l,5-... 

The suffixes -oic acid, -al, -amide and -nitrile are used to name acyclic compounds having one or two characteristic groups. Locants are not necessary, as these groups must be at the end of a chain. The suffixes -carboxylic acid, -carbaldehyde, -carboxamide and -carbonitrile are used when more than two groups are attached to chains or one or more groups are attached to cycles. 

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