4-Nitro- -nitril

Pentansaure 4-Chlor-4-nitro- -nitril E14a/3, 384 (R-CHC1-N02 + H2C = CH-CN)... 

In 1970, a new reaction, the displacement of a nitro group from a-nitro esters, a-nitro nitriles, a-nitro ketones, and a,a-dinitro compounds by nitroalkane salts, was described.3 These displacements, which are exemplified by the reaction presented in Eq. 7.1, take place at room temperature and give excellent yields of pure products. The reaction proceeds via a radical chain mechanism involving one electron-transfer processes as shown in Scheme 7.1 the details of the mechanism are described in a review.1... 

For unsaturated compounds with electron-withdrawing substituents (carb-oxyalkyl, nitro, nitrile, vinyl), polymerization can be initiated anionically (e.g., by OH, NH2 , or carbanions). 

E = ester, acyl, amide, nitro, nitrile, phosphono X = O, S, NR... 

Scheme 9.17 Intennediates of the hydrogenative cyclization of nitro nitriles leading to indoles.

Protiodenitration. Simple nitroalkanes are not reduced by 1, but a-nitro nitriles, esters, and ketones are selectively reduced by 1 under irradiation, with selective replacement of NO by H. The reduction occurs via an electron-transfer chain mechanism. Example ... 

Reduction of azides. Alkyi and aryi azides are reduced to primary amines by the combination of 1,3-propanedithiol and triethylamine (equation 1). The method is highly selective, and does not affect double or triple bonds, nitro, nitrile, carboxylic acid, amide, and ester groups. ... 

This reagent also reduces nitro, nitrile, and amide derivatives to amines, and carboxylic acids and anhydrides to alcohols. The yields of these reductions arc nearly quantitative. Esters and halobenzene derivatives are not reduced. 

Propansaure 2-Chlor-3-nitro- -nitril V/3, 943 (N02Cl-Add.) X/l, 94 (N02Cl-Add.)... 

Diazo- -methylester X/4, 547 2-Methyl-2-nitro- -nitril E19a, 747 (H -> CN)... 

Diazo- -ethylester E14b, 1128/1146 (Hydrazon-Oxidat.) 2,2-Dimethyl-3-nitro- -nitril X/l, 415 Pyrazolidin l,2-Dimethyl-3,5-dioxo-VII/4, 301... 

Azetidin 1 -(4-Acetamino-benzolsul-fonyl)-2-ethyl-3-oxo- E16c, 903 (aus R-S02-C-C0-CHN2) Butansaure 2,3-Dimethyi-2-(4-methyl-phenylsulfony])-3-nitro- -nitril E16d, 189 (C,C-Aufbau) Glutarsaure 2-(4-Methyl-benzol-sulfonylamino)- -1-methylester-5-nitril XV/1, 478 Pyrrol 2-Amino-3-methoxycarbo-nyl-l-(4-methyl-benzolsulfonyl)-... 

Aromatic nitro-nitrile compounds are easily reduced to the corresponding amino-nitrile derivative, and nitro oximes to the amino oximes ... 

If other active groups are present y or S to the reducible nitro group, hydrogenation can result in formation of nitrogen heterocyclic products. Several such cyclizations provide an entry to indoles, such as reductive cyclizations of dinitrostyrene 1 [equation (a)], of o-nitrobenzyl ketone 2 [equation (b)], and of nitro nitrile 3 [equation (c)] , all of them carried out on palladium-on-carbon. 

Reductive cyclization of a nitro-nitrile yields a fused pyrrole ring. 

---