Malonodinitrile alkylation

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)... 

Methine Dyes. The condensation products of 4-dialkylaminobenzaldehydes with cyano acetic esters have long been used to dye acetate fibers. Brilliant greenish yellow dyes with excellent lightfastness are obtained on polyester fibers with the corresponding condensation products of malonodinitrile. The sublimation fastness of this dye type can be improved by introducing suitable substituents into the alkyl residue of the amino group or by doubling the molecular size, e.g., C.I. Disperse Yellow 99, [25857-05-0] (11) [12,30,31],... 

N-monosubstituted aminomethylene derivatives of 1,3-dicarbonyls are accessible from trialkyl orthoformates, aromatic amines and 1,3-diketones. They are useful synthons for formation of hexahydroquinolinediones by treatment with KOH and malonodinitrile299. Depending on the substituents of the aniline derivative, replacement of the amine results from 1,4-addition-elimination of malonodinitrile or alkyl cyanoacetate to the en-aminedione and lead to quinolones300. The yields are not high but acceptable, since the starting materials are easily accessible (equation 223). 

For alkylation of malonodinitrile, dimethyl sulfoxide is recommended as solvent and sodium hydride as base, the reaction then occurring faster, under milder conditions, and in better yield than by other procedures. Wbenzyl-malonodinitrile, for instance, is thus obtained in 64-76% yield 412... 

The corresponding alkylation of the dinitrile [malonodinitrile, dicyanomethane, CH2(CN)2] is also easily effected, but, of course, the base must be changed to one that will not attack the cyano functionality and, as shown in Equation 9.107, sodium hydride (NaH) in dimethyl sulfoxide [DMSO, (CH3)2SO] is frequently the base (and solvent) of choice. 

The morpholine-promoted reaction of Af-alkyl piperi-dine-4-one with malonodinitrile and p-nitrostyrene derivatives in refluxing EtOH directly led to substituted tetrahydroisoquinoline derivatives in moderate to good yields [121], The reaction is initiated by a Knoevenagel condensation, in which a Michael addition/Thorpe-Ziegler sequence follows. Oxidation by air is the last step to occur providing the desired products. 

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