Reaction with dinitriles

In 2003, Saa and coworkers performed a comprehensive study on cationic [Cp Ru(CH3CN)3]PF6 complex-catalyzed [2 -I- 2 -I- 2] cycloaddition of 1,6-diynes to a,CT-dinitriles or electron-deficient nitriles (Scheme 3.13) [33]. The reaction with asymmetric electron-deficient alkynes could give the corresponding 2,3,6-trisubstituted pyridines in good yield. Based on their studies, they propose that the reactions with dinitriles seem likely to proceed via ruthenacyclopentadiene intermediates and the reactions with electron-poor nitriles via azaruthenacyclopentadienes. 

With dinitriles a slightly different procedure is necessary due to their water solubility. After the reaction has cooled, 150 ml of chloroform is added to the flask, and this mixture is then poured into saturated salt solution. Enough water is added to dissolve precipitated salt and the chloroform layer is separated. The aqueous layer is extracted once with chloroform. The combined extracts are then washed twice with salt solution, dried, and distilled. 

Aliphatic dinitriles, reaction with aliphatic diols, 87-88 Aliphatic diols, 77... 

Reaction of dinitriles with ammonia (cyclic imidines)... 

The synthesis of l,2-bis(thiophen-3-yl)maleic anhydride involves the dimerisation of a 3-cyanomethyl derivative of thiophene (1.45) by reaction with aqueous NaOH in the presence of CCl. Alkaline hydrolysis of the dinitrile (1.46) and dehydration produces the anhydride (1.47) as shown in Figure 1.12. ... 

The known dibromide 464 was converted in good yield to the dinitrile 465 by reaction with buffered potassium or sodium cyanide. Reaction of 2,5-dimethoxycarbonyl-3,4-dicyanomethylthiophene 465 with thionyl chloride and selenium oxychloride gave thieno[3,4-f]thiophene 466 and selenolo[3,4-f]thiophene 467, respectively (Scheme 57) <2002JOC2453>. In the case of thionyl chloride as the sulfur transfer reagent, an intermediate sulfoxide 468 must be involved, which then suffers a spontaneous base-catalyzed Pummerer reaction to give 466 in high yield. 

Dicyanomethane or Malononitrile (called Malonsaure-dinitril, Malonitril or Methylen-cyanid in Ger), NC.CH2.CN mw 66.06, N 42.41% col crysts, mp 31.6-32.4°, bp 108-09° at 17mm press, cryst d 1.191 at 20°, liq d 1.0494 at 35°, nfi 1.4139 at 34.2° prepd by esterification of cyanoacecic acid, and treatment of the ester with NH3 which leads to cyanoacetamide which, on reaction with phosphorous oxychloride or pentachloride, gives Dicyanomethane (Ref 1)... 

In the simplest case, reaction of a primary monoamine via a two-fold Michael reaction with acrylonitrile (bis-cyanoethylation) led to the dinitrile (Fig. 1.1). Subsequent reduction of the two nitrile functions - by hydrogenation with sodium borohydride in the presence of cobalt(II) ions - afforded the corresponding terminal diamine. Repetition (iteration) of this synthetic sequence, consisting in Michael addition followed by reduction, provided the first - structurally variable - access to regularly branched, many-armed molecules. 

Benzo[f]thiophene 710 is prepared by the dehydration of sulfoxide 709 with KOBu as a variant method of the Pummerer reaction. Irradiation of 710 affords 711 as a first example of Dewar benzo[dthiophene (Scheme 108) <1995TL3177>. Reaction of dinitrile 712 with thionyl chloride in the presence of EtsN yields thieno[3,4-dthio-phene 714 via Pummerer dehydration of the intermediate 713 <2000TL8843, 2002JOC2453>. 

Polymer cross-linking has also been achieved with l-arylsulfonyl-4-butyltetrazolin-5-ones (255) and with bistetrazolyl-m -phenylene molecules of this type (72GEP2226525). Tetrazole polymers of type (256) were prepared from thermal reactions of diazides with dinitriles. They are constituted as flexible fibers and have been claimed for use as thermally stable propellant binders and as plastics (68USP3386968). 

Interesting possibilities for the synthesis of new types of polysaccharide derivatives are offered by the reaction of addition to double bonds, which proceeds by a free-radical mechanism. The presence of initiators of free-radical polymerization (benzoyl peroxide, tert-butyl peroxide, dicumyl peroxide, dinitrile of azodiisobutyric acid), also irradiation with ultraviolet light, has effected the addition to 5,6-cellulosene of chloroform, carbon tetrachloride, methylmonochloroacetate, dimethyl-phosphite and other compounds that decompc under the conditions of a reaction with the formation of free radicals (45,46). The reaction proceeds as follows ... 

Miscellaneous Routes. Polyamides have been prepared by other reactions, including addition of amines to activated double bonds, polymerization of isocyanates, reaction of formaldehyde with dinitriles, reaction of dicarboxylic acids with dllsocyanates, reaction of carbon suboxide with diamines, and reaction of diazlactones with diamines. These reactions are reviewed in Reference 4. 

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