Malonodinitrile

Diketene is used to C-acetoacetylate aromatic compounds in the presence of aluminum trichloride [7446-70-0]. Benzene [71-43-2] and diketene react to produce acetoacet5lben2ene [93-91-4]. Pyrrole [109-97-7] and diketene react to produce 2-acetoacet5lpyrrole [22441-25-4]. The C-acetoacetyl derivatives of active methylene compounds such as cyanoacetates, malonodinitrile [109-77-3] and Meldmm s acid [2033-24-1], and olefins can be prepared using diketene. 

The only reaction of this type noted involved the reaction of pteridines, e.g. (415), with malonodinitrile (or cyanoacetamide), via ring opening to (416), with final [6 + 0 ( )] cyclization to give the 6-amino-7-nitrile (amide) (417) (73JCS(P1)1615, 73JCS(P1)1974). 

Ohta and Kato found that in the presence of bases the OMe group of 22 may be displaced by compounds with active methylene groups (ethyl cyanoacetate, malonodinitrile), yielding 27, which can be deprotonated to a methylenepyran derivative (28, R = CN, B =CNorC02Et). 

The more conventional nucleophiles obtained from compounds with active methylene groups, such as malonodinitrile or ethyl cyanoacetate give similar methylenepyrans (28, R = Il =CN... 

A convenient method leading to pyrans (38) consists in the nucleophilic addition of R anions to 2,6-disubstituted pyrjdium salts, in which the y-position (secondary carbonium ion) is more reactive than the a-positions (tertiary carbonium ions), in opposition to the reactivity of 2,4,6-trisubstituted pyrylium salts.Krohnke and Dickore as well as Dimroth and WolH showed that 2,6-diphenyl-pyrylium salts add the anions R of nitromethane, 1,3-diketones, malonodinitrile, ethyl cyanoacetate, and benzoylacetonitrile. Similar reactions are known in the flavylium series. -Nonactivated R ... 

Disodium salt of 2-(dimercaptomethylene)malonodinitrile (82) afforded with 81 tricyclic compound 83 (Eq. 11) (91ZOR185). 

The condensation between enaminones and cyanoacetamide is a well-established method for the synthesis of 2-pyridones (see c, Scheme 2, Sect. 2.1), and the use of malonodinitrile instead of the amide component has also been shown to yield 2-pyridones [39-41]. Recently, Gorobets et al. developed a microwave-assisted modification of this reaction suitable for combinatorial synthesis, as they set out to synthesize a small library of compounds containing a 2-pyridone scaffold substituted at the 3, 5, and 6-positions [42]. The 2-pyridones were prepared by a three-component, two-step reaction where eight different carbonyl building blocks were reacted with N,N-dimethylformamide dimethyl acetal (DMFDMA) to yield enaminones 7 (Fig. 2). The reactions were performed under solvent-free conditions at el-... 

The reaction of iV-amino-2-chloro-5-phenyl[l,2,4]triazole 364 with malonodinitrile, in the presence of triethylamine, in refluxing ethanol gives intermediate 365 that spontaneously cyclized to give 6-amino-7-cyano-3-phenyl-pyrazolo[5,l-c][l,2,4]triazole 62 in 70% yield (Equation 69) <1996SC3827>. 

The products from the N-alkylation of (anilinomethylene)malonodinitriles with a-haloacetic esters and a-haloketones spontaneously cyclize to produce pyrroles (Scheme 5.3) [21]. When the A -acylated product of the reaction of the dinitrile with ethyl chloroformate is treated with an arylamine, 5-cyanopyrimidones are obtained [21]. 

Alkylation of p-dicarbonyl compounds, cyano esters and malonodinitrile (Table 6.9)... 

One-pot conversions of 2-hydroxy(acylbenzenes) with anhydrides or acid chlorides to produce coumarins [52-54] and flavones [54-58] under mild liquiddiquid or solidtliquid two-phase conditions via a Baker-Venkataraman type reaction (Scheme 6.19) are catalysed by quaternary ammonium salts. 3-Substituted coumarins are produced from salicylaldehyde and malonodinitrile, or substituted acetonitriles, in high yield (>85%) in a one-pot catalysed sequential aldol-type reaction and cycliza-tion in the absence of an added organic solvent [59]. When 2 -hydroxychalcones are reduced under catalytic two-phase conditions with sodium borohydride, 2,4-cis-flavan-4-ols are produced [60] (see Section 11.3). 

Anomalous products have been noted with acetophenone, with malonodinitrile, with malonodiamide and substituted malon-... 

Triamterene Triamterene, 2,4,7-triamino-6-phenylpteridine (21.5.13), is synthesized in by the following scheme. Reacting guanidine with malonodinitrile gives 2,4,6-triaminopyrimi-dine (21.5.11). This undergoes nitrosation by reacting it with nitric acid, which results in the... 

Surprising effects can also be observed when solvent mixtures are used to dissolve a polymer. There are examples where mixtures of two non-solvents act as a solvent vice versa, a mixture of two solvents may behave like a non-solvent. For example, polyacrylonitrile is insoluble in both, nitromethane and water, but it dissolves in a mixture of the two solvents. Similar behavior can be observed for polystyrene/acetone/hexane and poly(vinyl chloride)/acetone/carbon disulfide. Examples of systems where the polymer dissolves in two pure solvents but not in their mixture are polyacrylonitrile/malonodinitrile/dimethylforma-mide and poly(vinyl acetate)/formamide/acetophenone. These peculiarities are especially to be taken into account if one wants to adjust certain solution properties (e.g., for fractionation) by adding one solvent to another. 

Similar results were encountered in the reaction of 69 (generated thermally from the corresponding 2,5-dihydro-1,3,4-thiadiazole) with benzylidene malonodinitrile or a-cyano-substituted cinnamates (97). In these cases, seven-membered lactams or... 

In solution, the dynamic H-NMR spectrum indicated the presence of 1 1 and 1 2 complexes of [18Jcrown-6 with nitromethane, acetonitrile and malonodinitrile. The thermodynamic complexation constants for the 1 1 complexes are listed in Table 2. 

Malonodinitrile Complex of N,N -bis(2-cyanoethyl)-l,10-diaza-4,7,13,16-tetraoxa-cyclooctadecane (5b)... 

Figure 5 Crystal structures of (a) [18]crown-6 complex with two malonodinitrile molecules (b) binaphthol crown ether complex with water (reproduced with permission from 77CB2249 and 78AX(B)3387)...

Unexpectedly, 2//-pyran structure 72 is reported for products prepared by adding dienones 71 to malonodinitrile.116... 

For malonodinitrile (maldn) and succinodinitrile (sucdn), V0(maldn)s64-2H20 V0(sucdn)S04-2H20 were prepared according to reaction (24). 443... 

Amino-3-cyanofurans (307) are obtained by base catalyzed condensation of the acyloins (306) with malonodinitrile, and on acid hydrolysis yield the butenolides (308) (Scheme 80) (66CB1002). Diketene and an isocyanide react to give the lactone (309) in the presence of a tertiary base (73GEP2222405). When diphenylketene is treated with bis(cycloocta-l,5-diene)nickel and pyridine, the complex Ni(py)2(Ph2C=CO)2 is formed which is converted into compound (310) by carbon monoxide (78JOM(l52)C29). 

Amino-3-cyanofurans (530) are obtained by base catalyzed condensation of acyloins (529) with malonodinitrile (66CB1002). 

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