M. F. Gordeev

Synthesis of the N,S-acetals of diacyl- and alkoxycarbonyl(acyl)ketenes with β-dicarbonyl compounds, organic thiocyanates, and nickel(2+) complexes

An effective method is proposed for the production of the N,S-acetals of diacylketenes and acyl(alkoxycarbonyl)ketenes, based on the addition of methylene-activeβ-diketones andβ-ketoesters to alkyl and aryl thiocyanates catalyzed by Ni(2+) acetylacetonate. Methods are indicated for the synthetic utilization of diacetylketene N,S-acetals and include their conversion to ketene aminals, chelation with boron compounds, and deacylation of derivatives of monoacetylketene with methanol in the presence of Co(2+) acetate.

Synthesis of derivatives of 4-alkylthiouracil, cytosine, pyrido[2,3-d]pyrimidine, and pyrimido[4,5-d]pyrimidine from the N,S- and N,N-acetals of diacetylketene and isocyanates

The action of alkyl and aryl isocyanates on the N,S-acetals of diacetylketene leads to the formation of 4-alkylthio-5-acetyl-1-alkyl(aryl)-6-methyl-1H-pyrimidin-2-ones (derivatives of 4-alkylthiouracils). The reaction of the synthesized thiouracils with amines or the reaction of the N,N-acetals of diacetylketene (N,N-ADK) with an equi-molar amount of aryl isocyanates leads to the formation of substituted 4-amino-5-acetyl-1H-pyrimidin-2-ones (derivatives of cytosine). From the latter and isocyanates or directly from N,N-ADK and an excess of the isocyanate, derivatives of 4-methylene-1H,3H, 4H-pyrimido[4,5-d]pyrimidine-2,7-dione were obtained. The exception was the condensation of 3-[N-(4,6-dimethyl-2-pyrimidinyl)diaminomethylene]pentane-2,4-dione with aryl isocyanates, which led to 3H,8H-pyrido[2,3-d]pyrimidine-2,5-diones.

Synthesis of functional derivatives of trifluoromethylpyrimidines from acetylacetone, trifluoroacetonitrile, and aryl isocyanates

Abstract1, 1,1-Trifluoro-2-amino-3-acetyl-2-penten-4-one was obtained by the addition of acetylacetone to trifluoroacetonitrile in the presence of catalytic amounts of nickel acetylacetonate. The reaction of 1,1,1-trifluoro-2-amino-3-acetyl-2-penten-4-one with aryl isocyanates gave 1-aryl-5-acetyl-6-methyl-4-trifluoromethyl-1H-pyrimidin-2-ones.

Synthesis of diacylketene and alkoxycarbonyl(acyl)ketene N,N-acetals by the reaction of β-diketones and β-ketoesters with monosubstituted cyanamides

Abstractβ-Diketones and β-ketoesters react with monosubstituted cyanamides in the presence of catalytic amounts of Ni(acac)2 to form diacyl- and alkoxycarbonyl(acyl)ketene N, N-acetals (DKAs and AKAs, respectively). The interconversion of E and Z isomeric forms of AKAs was studied by means of1H and13C NMR spectroscopy.

5-Acyl-4-amino-2-phenyl-1,3-oxazin-6-ones

Intramolecular cyclization of acyl(ethoxycarbonyl)keteneN-benzoylaminals in boiling Ph2O gives 5-acyl-4-amino-2-phenyl-1,3-oxazin-6-ones.

Reaction of acetylacetone with cyanamide in the presence of catalytic amounts of nickel acetylacetonate

ConclusionsThe reaction of acetylacetone with cyanamide in the presence of Ni(acac)2 involves the addition of the CH2 group at the nitrile group of cyanamide with the formation of 3-(diaminomethylene)pentane-2,4-dione (III) and the products of its transformations, namely, N-acylketenaminals (IV) and (V).

Synthesis of 1,3-thiazoline derivatives from ?-dicarbonyl compounds and phenacyl thiocyanate

Acetylacetone and ethyl acetoacetate undergo addition at the C≡N bond of phenacyl thiocyanate in the presence of Ni(acac)2 to give the respective keteneN, S-acetals, which undergo smooth cyclization to afford 2-methylene-4-phenyl-1, 3-thiazoline derivatives when refluxed in THF.

Synthesis of derivatives of the new heterocyclic system pyrimido[4′,5′:4,5]pyrimido[1,2-a]benzimidazole

Abstract3-Phenyl-5-methyl(phenyl)-1H,3H-pyrimido[4′,5′:4,5]pyrimido[1,2-a]benzimi-dazole-2,4-diones were obtained by the cyclization of N-phenyl-N′-[3-ethoxycar-bonyl-4-methyl(phenyl)pyrimido [1,2-a]benzimidazol-2-yl]ureas by the action of potassium carbonate. 2-Methyl-5-phenyl-1H-pyrimido[4′,5′:4,5]pyrimido[1,2-a]benzimidazol-4-one was obtained by the reaction of N′-3-ethoxycarbonyl-4-phenylpyrimido[1,2-a]benzimidazol-2-yl]-N,N-dimethylacetamidine with ammonium acetate in ethanol. The synthesized compounds are members of a new heterocyclic system. The molecular and crystal structure of the solvate of 3-phenyl-5-methyl-1H,3H-pyrimido[4′,5′:4,5] pyrimido[1,2-a]benzimidazole-2,4-dione with two molecules of DMF was studied by x-ray crystallographic analysis.

Synthesis of 2,4-diamino-5-acetyl(ethoxycarbonyl)pyrimidines from β-dicarbonyl compounds and dicyandiamide and their use for building a pyrimido[4,5-d]pyrimidine system

Abstract2,4-Diamino-5-acetyl(ethoxycarbonyl)-6-methyl(phenyl)pyrimidines were obtained by the reaction of acetylacetone and β-ketocarboxylic acid esters with dicyandiamide in the presence of Ni(OAc)2. It was shown that annelation of the pyrimidine ring with this compound provides a convenient method for building the pyrimido[4,5-d]-pyrimidine system. New derivatives of 2-aminopyrimido[4,5-d]pyrimidine, 7-amino-3H-pyrimido[4,5-d]-pyrimidin-4-one, and 7-amino-1H,3H-pyrimido[4,5-d]-pyrimidine-2,4-dione were synthesized.

Cycloaddition of α-dialkylborylamino-n-heterocycles to cyanamides

Abstractα-Diisopropylaminopyridine and 2-dipropylborylamino-1-methylbenzimidazole react with cyanamides to give chelate [4+2]-cycloadducts. X-ray crystallography has been used to establish the molecular and crystal structure of the product of the reaction of α-diisopropylaminopyridine and benzoylcyanamide.