Pyrimidines

Condensation of substituted acetophenones with arylidenebisureas at 50° C has given 2,7-di-oxo-4,5,8-triaryldecahydropyrimido[4,5-d]pyrimidines. The latter, onboiling with CF₃COOH, are converted into 2-oxo-4,5-diaryl-5H-indeno[1,2-d]pyrimidines, whose structure has been confirmed by spectral methods and by independent synthesis from 3-phenyl-1-indanone and arylidenebisureas.For part XXIII, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 5, pp. 691–696, May, 1970.     

Pyrimidines

Dehydrogenation of 2-hydroxy-4-phenyl-3, 4, 5, 6-tetrahydrobenzo[h]quinazoline with Pd/C, diphenyl disulfide, chloranil, and N-bromosuccinimide, was investigated. Dihydroderivatives of 2-hydroxy-4-phenylbenzo[h]quinazoline were obtained. The action of N bromosuccinimide led to dehydrogenation and bromination. Treatment of 2-hydroxy-4-phenylbenzo[h]quinazoline and its bromine derivative with phosphorus oxychloride, followed by hydrogenation, gave 4-phenylbenzo[h]quinazoline. The structures of the compounds prepared are confirmed by spectroscopic data.For Part II see [1].     

Pyrimidines

The reaction of methylenebisurea with 5-amino-1-R-pyrazoles and 3-ureido-1-phenylpyrazole gives 1- and 2-R-6-oxo-4,5,6,7-tetrahydropyrazolo[3,4-d]pyrimidines, respectively. The 1-R-6-oxo-4,5,6,7-tetrahydropyrazolo[3,4-d]pyrimidines are readily dehydrogenated to 1-R-6-hydroxypyrazolo[3,4-d]pyrimidines. The 2-R-6-oxo-4,5,6,7-tetrahydropyrazolo[3,4-d]pyrimidines could not be dehydrogenated.See [1] for communication XXXIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1696–1699, December, 1972.     

Pyrimidines

The synthesis of 2-amino-6-cyano-4-methylpyrimidine and 2-amino-4,6-dicyanopyrimidine from the corresponding chloro derivatives is described. It is shown that the reaction of ammonia with chlorodicyanopyrimidine proceeds in two directions one observes substitution of either the chlorine atom or the cyano group.See [1] for communication LXI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 821–824, June, 1977.     

Pyrimidines

The reaction of phenylacetone with benzylidenebisurea (BBM) has given 2-hydroxy-4, 5-diphenyl-6-styryl-3, 4-dihydropyrimidine (I). The structure of I has been confirmed by its independent synthesis from 1, 4diphenylbut-3-en-2-one and BBM and also by a number of subsequent transformations.For part XVIII, see [1]     

Pyrimidines

Pyrimidine-2-aldoxime and 4,6-dimethylpyrimidine-2-aldoxime were obtained by oximation of the corresponding aldehydes. On the basis of spectral data, it was shown that the oximes have the syn configuration. syn-4, 6-Dimethylpyrimidine-2-aldoxtme is converted to the corresponding anti isomer by photochemical isomerization. 1-Methyl-2-oximidomethylpyrimidinium iodide was obtained by the action of methyl iodide on pyrimidine-2-aldoxime.See [1] for the preceding communication.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1422–1424, October, 1972.     

Pyrimidines

The preparation of dimethylacetals and oximes of 2(6)-formyl-4-phenylpyrimidine N-oxides from the corresponding bromomethyl derivatives is described. A syn configuration was assumed for the oximes from the PMR spectra.See [1] for communication LXVI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1397–1399, October, 1978.     

Pyrimidines

A comparative study was made of the addition of ethanol at the carbonyl group of some 2-formylpyrimidines and aldehydes of other series in which the carbonyl group is activated by the effect of an electron-acceptor grouping (chloral, p-nitrobenzaldehyde, and 2-formylpyridine). It is shown that 2-formylpyrimidines have high reactivities that are comparable with the reactivity of chloral.See [1] for communication XXIX.Translated from Khimiya Geterotsiklicheskih Soedinenii, No. 6, pp. 838–842, June, 1971.     

Pyrimidines

It is shown that it is possible to use heterocyclic ketones to synthesize condensed pyrimidine derivatives in the case of 1-(p-toluenesulfo)-1,2,3,4-tetrahydroquinol-4-one, which on reaction with benzylidenebisurea gives 2-hydroxy-4-phenyl-6-(p-toluenesulfo)-3, 4, 5, 6-tetrahydropyrimido [5,4-c] quinoline, and the latter, after dehydrogenation via the 2-hydroxy, 2-chloro derivatives, was converted to 4-phenylpyrimido [5, 4-c] quinoline, a new heterocyclic system.For Part IV see [13].     

Pyrimidines

It is shown that the reaction of benzalbisurea with 3-amino-5-hydroxy-1-R-pyrazoles gives 1-R-dipyrazolo[3,4-b:4,3-e]pyridine (R=CH₃) or a spiro(pyrazole-4,5-pyrimidine) derivative (R=C₆H₅). Similar reactions of benzalbisurea with 3-hydroxy-5-amino-1-methylpyrazole give 2-methyldipyrazole[3,4-b:4,3-e]pyridine or substituted tetrahydropyrazolo[3,4-d] pyrimidine. Only the corresponding dipyrazolo[3,4-b:4,3-e]pyridines are formed in the reaction of 1-methylhydroxyaminopyrazoles with methylenebisurea.See [1] for communication XXXIX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 823–827, June, 1974.     

Pyrimidines

Some hydrogenation products of 2-hydroxy-4-phenylbenzo [h]quinazoline are acetylated with acetic anhydride. Mono and diacetyl derivatives are obtained, depending on the extent of hydrogenation of the quinazoline ring. From spectroscopic data structures are put forward for these compounds. Formation of a diacetyl derivative from 2-hydroxy-4-phenyl-3, 4, 5, 6-tetrahydrobenzo [h]quinazoline offers support for a previously advanced view regarding its structure.For Part III see [1].     

Pyrimidines

In the condensation of benzalbisurea with 1-methyl-3,5-diaminopyrazole the pyrimidine ring closes through the amino group of pyrazole in the 5 position to give 1-methyl-4-phenyl-3-benzalamino-6-oxo-4,5,6,7-tetrahydropyrazolo[3,4-d]pyrimidine. The latter is converted to 1-methyl-4-phenyl-3-amino-6-oxo-6,7-dihydropyrazolo [3,4-d]pyrimidine by dehydrogenation and subsequent hydrolysis of the benzylidene group.     

Pyrimidines

3-Arylbenzo[f]quinazolines were obtained by reaction in acetic or propionic acid of -naphthylamine, ammonia, and aromatic aldehydes containing an NR₂ or OH group. A mechanism is proposed for the formation of monoarylbenzo[f]quinazolines from the corresponding intermediate 1,3-diaryldihydrobenzo [f] quinazolines by acid cleavage of the C-aryl bond in the 1 position. This mechanism was confirmed experimentally by establishment of the fact of cleavage of 1,3-bis (p-methoxyphenyl)-1,2-dihydrobenzo[f] quinazoline when the acidity of the medium is increased; 3-(p-methoxyphenyl) benzo [f] quinazoline and anisole were obtained in the reaction products. Condensation in the presence of formic acid gave -arylidene-N-formyl--naphthylamines rather than arylbenzo [f] quinazolines.See [1] for communication LXIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1265–1271, September, 1978.     

Pyrimidines

A method for the preparation of 2-amino(acetamido)pyrimidines by condensation of α,β-unsaturated carbonyl compounds with guanidine (acetylguanidine) was developed.     

Pyrimidines

The condensation of -substituted acetophenones with benzylidenebisurea in an acid medium has given 5-R-2-oxo-4,6-diphenyl-1,2,3,4-tetrahydropyrimidones. The analogous condensation of propiophenone forms 5-methyl-2-hydroxy-4,6-diphenylpyrimidine. The tetrahydro derivatives obtained are readily dehydrogenated to 5-R-2-hydroxy-4,6-diphenylpyrimidines.For part XX, see [1].     

Pyrimidines

The reaction of cyclohexanone with arylidenebisureas (e.g. benzal-bisurea) in an acid medium has given 4, 4-diaryl-2, 2-dioxo-5, 5-trimethylene-6, 6-spirobishexahydropyrimidines (II). The acid hydrolysis of IIa (aryl-C₆H₅) in the presence of 2, 4-dinitrophenylhydrazine leads to the 2, 4-dinitrophenylhydrazone of 2-hydroxy-8-oxo-4-phenyl-5, 6, 7, 8-tetrahydroquinazoline (IV). Compound IV was also obtained by the ozonization of 2-acetoxy-8-benzal-4-phenyl-5, 6, 7, 8-tetrahydroquinazoline (IX) and subsequent decomposition of the ozonide with a solution of 2, 4-dinitrophenylhydrazine. The structure of the compounds obtained was confirmed by means of their IR, UV, and PMR spectra. Corresponding 6, 6-spirobishexahydropyrimidines have also been obtained from 2-methylcyclohexanone, acetone, and methyl ethyl ketone and benzalbisurea.For part XIV, see [1].     

Pyrimidines

A new method was developed for the synthesis of substituted pyrazolo[3,4-d]pyrimidines by the condensation of 1-alkyl(aryl)-3- and 5-aminopyrazoles with arylidenebisureas.See [1] for communication XXVIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 535–539, April, 1971.     

Pyrimidines

2-Diazoacetyl-4, 6-diphenylpyrimidine is prepared from 2-chloro-4, 6-diphenylpyrimidine via the nitrile and the corresponding acid, and it is readily converted to 2-bromoacetyl and 2-chloroacetyl-4, 6-diphenylpyrimidine. It was not possible to bring about the Wolff reaction.For Part IV see [12].     

Pyrimidines

The corresponding 2-pyrimidoylacetate esters (I, II) and 2-pyrimidoyl-acetonitrile (V) were obtained by condensation of pyrimidine-2-carboxylic acid esters with methyl acetate or acetonitrile. The structures of the tautomeric forms were determined by IR and PMR spectroscopy. The effect of a solvent and protonation of the pyrimidine ring on the ketone-enol equilibrium was examined.     

Pyrimidines

The reaction of substituted 3-methyl-5-pyrazolones with arylidenebisureas has been studied. Substituted spiro[pyrazole-4, 5-pyrimidines] have been obtained from 1-phenyl- and 1-benzyl-3-methyl-5-pyrazolones. When only one hydrogen atom was present in the ring of the 3-methyl-5-pyrazolone, the corresponding -ureidobenzyl derivative was obtained.For communication XI see [1].