Pedro Victory

The reaction of malononitrile with chalcone: a controversial chemical process

Abstract Given the significant discrepancies in the several reported results on the reaction of chalcone (1,3-diphenyl-2-propne-1-one) (1) with malononitrile (2), a careful reinvestigation was carried out. Depending upon the reaction conditions either the open-chain Michael adduct (4), an alkoxypyridine (5), an aminoisophthalonitrile (6) or a cyclohexanol (7) is obtained. However, no 4H-pyran could be isolated from this reaction.

A Non-obvious Reaction Pathway in the Formation of 2-aminobenzene-1,3-dicarbonitriles From Alpha,Beta-unsaturated Ketones Or Aldehydes

Key intermediates demonstrating a non-obvious reaction pathway leading to 2-aminobenzene-1,3-dicarbonitriles from enones have been isolated and characterised in tire reaction between (E)-4-phenyl-3-butene-2-one and propanedinitrile in a basic hydro-alcoholic medium. (E)-4-Phenyl-3-butene-2-one reacts with three molecules of propanedinitrile to give a 6-amino-2-iminobicyclo[2.2.2]-5-octene-1,3,3,5-tetracarbonitrile system which evolves to a substituted cyclohexadiene by elimination of the sodium salt of 1,1,1-tricyanomethane. Further oxidation leads to the final 2-aminobenzene-1,3-dicarbonitrile. The proposed pathway involves more steps and more difficult transformations than previously presented for similar systems. We can not exclude a simpler reaction pathway derived from the double Michael and Knoevenagel adduct of (E)-4-phenyl-3-butene-2-one and propanedinitrile, however we have not found any evidence for this simpler process.

Synthesis of 4-Amino-8-cyanoquinazolines from Enones and Enals

The treatment in a sodium methoxide/methanol solution of α,β-unsaturated enones or aldehydes with propanedinitrile in a 1:2 molar ratio led to 2-aminobenzene-1,3-dicarbonitriles. These compounds afforded 4-amino-8-cyanoquinazolines by reaction with formamide or guanidine

A simple synthesis of 2-methoxypyridine-3-carbonitriles

The condensation of propanedinitrile with several enals or enones in a methanol-sodium methoxide system provides a one-step route to 2-methoxypyridine-3-carbonitriles. Together with these compounds substituted 2-aminobenzene-1,3-dicarbonitriles, were obtained as by-products

Two step synthesis of pyrido[2,3-d]pyrimidines from acyclic precursors. Cyclization of 2-cyanamino-4,6-diphenylpyridine-3-carbonitrile by Hydrogen Halides

Abstract The cyclization of 2-cyanamino-4,6-diphenylpyridine-3-carbonitrile promoled by hydrogen halides takes place regiospecifically leading in all the cases to the 4-amino-2-halogen substituted pyrido[2,3-d]pyrimidine. This procedure completes a flexible and straightforward approach to aromatic pyrido[2,3-d]pyrimidines from acyclic precursors.

A synthesis of 1,2,3,4-tetrahydro-1,6-naphthyridines

8-Cyano-3,4-dihydro-1,6-naphthyridin-2(1 H)-ones were obtained by nucleophilic substitution of the methoxyl group of 5-cyano-3,4-dihydro-6-methoxy-2(1 H)-pyridones (5a-d) by malononitrile or cyanoacetamide followed by cyclization in acidic or basic medium

1,2,3,4-Tetrahydro-1,6-naphthyridines. Part 2. Formation and Unexpected Reactions of 1,2,3,4-Tetrahydro-7H-pyrano[4,3-b]pyridine-2,7-diones

The nucleophilic substitution of the enol methoxy group of pyridones (1) by methyl cyanoacetate led to (Z)-5-cyano-6-cyanomethoxycarbonylmethylenepiperidones (6), which underwent cyclization in acid medium to 1,2,3,4-tetrahydro-7H-pyrano[4,3-b]pyridine-2,7-diones (7). Surprisingly, the treatment of 7 with ammonia yielded the 5-cyano-6-cyanomethyl substituted pyridones (11) which were not accessible by reaction of 1 with NaCH 2 CN

Synthesis of 2-cyanamino-4,6-diphenyl-pyridine-3-carbonitrile

The nucleophilic displacement of bromo, alkylthio and alkylsulphonyl groups from pyridine systems by cyanamide is studied in order to obtain a previously unreported 2-cyanaminopyridine-3-carbonitrile. A one-step synthesis of the same compound by cyclization in basic medium of the non-isolated Michael adduct of (E)-1,3-diphenylpropenone and propanedinitrile is also described

Synthesis of 4-dimethoxymethyl-6-hydroxy-2-methoxynicotinonitrile: a suggested mechanism revision

Methyl 4,4-dimethoxy-3-oxobutyrate (1) condenses with malonodinitrile (2) in methanolic sodium methoxide to form 4-dimethoxymethyl-2-methoxypyridine-3-carbonitrile (3a). A previously proposed interpretation of this reaction is shown to be only one of several which allow the formation of one isomer or another [6-alkoxy-2-hydroxy-(4) or 2-alkoxy-6-hydroxy-3-cyano-pyridines] depending on the pH of the medium.