Nitrogen- and sulfur -containing heterocycles

A number of derivatives of pyrimido [4, 5-b]-[1, 4]-6-thiazinone have been obtained by the reaction of 2, 5-diamino-4-methyl-6-mercapto-and 4-methoxy-5-amino-6-mercaptopyrimidines with -halo acids.     

Research on nitrogen and sulfur-containing heterocycles

2-Mercapto-3-amino-5-chloropyridine reacts with phenacyl halides to yield 2-phenacylmercapto-3-amino-5-chloropyridines and 2-aryl-7-chloro-3H-pyrido[2, 3-b][1, 4]thiazines.For part V, See [11].     

Investigation of nitrogen- and sulfur-containing heterocycles

The synthesis of two-ring 1,4-thiazine systems was previously accomplished on the basis of the reaction of o-amino mercapto derivatives of pyridine and pyrimidine with dicarbonyl compounds — halo -keto esters and halo -diketones. In the present paper it is shown that the primary products of this reaction are S--keto-alkylmercapto derivatives, which are subsequently cyclized to the corresponding hydroxy amino compounds. The latter are converted to N-acylamino-S--carbethoxy (keto)alkylmercapto derivatives under the influence of an alkaline agent. The indicated compounds were isolated and characterized [2, 3].See [1] for communication 36.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 250–253, February, 1979.     

Investigation of nitrogen- and sulfur-containing heterocycles

5-Acylamino-6-acylmethylmercaptopyrimidines are formed by reaction of 5-amino-6-mercaptopyrimidines with halo--diketones in alkaline media, while 7-acylpyrimido[4,5-b]-[1, 4]thiazines are formed in close-to-neutral media.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 120–123, January, 1973.     

Investigation of nitrogen- and sulfur-containing heterocycles

Catalytic hydrogenation of cyanoacetyl-, -cyanopropionyl-, and cyanobutyrylurethanes in aqueous media in the presence of Raney nickel and the hydrochlorides of o- and p-toluidines, o- and p-alkoxyphenylamines, p-aminoacetophenone, ethyl p-aminobenzoate, and ethyl p-aminophenylacetate, and in the presence of sodium p-aminosalicylate and acetic acid gave the corresponding -arylaminoacryloyl(or -alkylacryloyl)urethanes, which were converted, without isolation in the pure state, to 1-aryl- and 1-aryl-5-alkyluracils by heating in dilute alkali solutions.See [1] for communication XXV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1280–1282, September, 1974.     

Investigation of nitrogen- and sulfur-containing heterocycles

The chlorine atom in 4-chloro-6,7-dihydro-8H-pyrimido[5,4-b][1,4-oxazin-7-ones is replaced by amine residues and mercapto and methoxy groups and can also be removed in the presence of Pd/C. Pyrimidooxazin-7-ones are alkylated in the 8 position, while, depending on the conditions, the 4-mercapto derivatives are alkylated either at the mercapto group or simultaneously at the mercapto group and in the 8 position.     

Investigation of nitrogen- and sulfur-containing heterocycles

The reaction of (3-amino-6-chloro-2-pyridylmercapto)oxalacetic ester with ammonia, benzylamine, morpholine, and piperidine yielded amides, while the reaction of the ester with hydrazine hydrate gave [2-(ethoxycarbonylmethylthio)-3-pyridyl]oxamic acid hydrazide. The benzylamide and morpholide of this acid were obtained by treatment of 2-chloro-6-hydroxy-6,7-di(ethoxycarbonyl)dihydropyridothiazine with the appropriate amines. The reaction of 2-mercapto-3-amino-6-chloropyridine with chlorooxalacetic ester in the presence of alkali yielded potassium [2-(ethoxycarbonylmethylthio)-3-pyridyl]oxamate.See [1] for communication XXI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1502–1505, November, 1971.     

Investigation of nitrogen- and sulfur-containing heterocycles

The reaction of 5-amino-4-chloro- and -4-methoxy-6~mercaptopyrimidines with 4-methoxy-, 4-amino-, and 2,4-diethoxyphenacyl chlorides has yielded 5-amino-4-chloro- and -4-methoxy-6-phenacylthiopyrimidines. The reaction of 2, 5-diamino-4-methyl-6-mercaptopyrimidine with 4-methoxyphenacyl chloride has yielded 2-amino-6-hydroxy-6-(4-methoxyphenyl)-4-methyl-5, 6-dihydropyrimido[4, 5-b]-1,4-thiazine, and that with 4-aminophenacyl chloride has yielded the corresponding 7H-pyrimido[4, 5-b]-1,4-thiazine.For part IV, see [1].     

Investigation of nitrogen- and sulfur-containing heterocycles

A number of derivatives of a new heterocyclic system — pyrimido[5,4-b][1,4]-7-oxazinone- were obtained by the reaction of substituted 5-hydroxy-6-aminopyrimidines with ethyl esters of-halocarboxylic acids.See [1] for communication XXIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1285–1288, September, 1972.     

Investigation of nitrogen-and sulfur-containing heterocycles

Reaction of 4-chloro-5-hydroxy-6-aminopyrimidine and its 2-methyl derivatives with -chloroacetoacetic ester gave the corresponding 4-chloro-6-carbethoxy-8H-pyrimido-[5,4-b][1,4]oxazines, which were converted to 4-aminopyrimidooxazines by reaction with amines.See [1] for communication XXVIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1694–1696, December, 1973. Original article submitted.     

Investigation of nitrogen- and sulfur-containing heterocycles

The corresponding N-(3-pyridyl)hydroxamic acid derivatives were obtained by reductive desulfuration of [2-(ethoxycarbonylmethylthio)-6-chloro-3-pyridyl]hydroxamic acid amide, benzylamide, and morpholide. The amides were synthesized by reaction of [2-(ethoxycarbonylmethylthio)-6-chloro-3-pyridyl]hydroxamic acid ester with diethylaminoethylamine and pyrrolidine. Heating of the ester and morpholide of [2-(ethoxycarbonylmethylthio)-6-chloro-3-pyridyl]hydroxamic acid with H₂SO₄ gives 2-chloropyrido[2,3-b] [1,4]thiazin-6-one.See [1] for communication XXVI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 676–678, May, 1973.     

Investigation of nitrogen- and sulfur-containing heterocycles

2-Mercapto-3-ureido-6-chloropyridine reacts with the ortho, meta, and para derivatives of phenacyl halides to give 2-phenacylthio-3-ureido-6-chloropyridines, which are readily cyclized to 6-arylpyrido[2,3-b][1,4]thiazines regardless of the presence or absence of a substituent in the meta and para positions of the benzene ring.See [1] for communication XXIX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 798–800, June, 1974.     

Investigation of nitrogen- and sulfur-containing heterocycles

The reaction of o-aminomercapto derivatives of pyrimidine, pyrazine, and pyridine, with -halo acid nitriles was investigated. The corresponding cyanoalkylthio heterocycles, which were converted to 6-amino derivatives of pyrimido[4,5-b]-, pyrazino[2,3-b]-, and pyrido-[2,3-b]-1,4-thiazines, were obtained. The structures of the substances obtained were confirmed by IR, UV, and PMR spectroscopy.See [10] for communication XXII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 944–948, July, 1972.     

Oxidative imination of sulfur-containing heterocycles

For the first time, the sulfur heteroatom of 4-oxothiazolidines has been iminated with sodium salts of chloroamides of arenesulfonic acids and N-chloroamides of carboxylic acids. The effect of the substituents and the size of the ring on the ability of the ring sulfur atom to undergo oxidative imination was studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 609–612, May, 1979.     

A study of nitrogen- and sulfur-containing heterocycles

The catalytic hydrogenation of N--cyanoacylureas and 1-alkyl-3--cyanoacylureas in the presence of hydrochlorides of aromatic amines has given N--arylaminoacryloyl-, 1-alkyl-3--arylaminoacryloyl-, N--alkyl--arylaminoacryloyl-, and 1-alkyl-3--alkyl--arylaminoacryloylureas. The action of N- -phenylaminoacryloyl- and 1-methyl -3- -phenylaminoacryloylureas of ethanolic hydrogen chloride has given uracil and 1-methyluracil.For Communication IX, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 6, pp. 847–850, June, 1970.     

An investigation of nitrogen- and sulfur-containing heterocycles

The reaction of 3-amino-6-chloro-2-mercaptopyridine with ortho-substituted phenacyl halides has been investigated. Two types of intermediate compounds have been isolated: 3-amino-6-chloro-2-(phenacylthio)pyridines and 2-aryl-2-hydroxy-1,2-dihydro-3H-pyrido[2,3-b][1,4]thiazines. Boiling 3-amino-6-chloro-2-mercaptopyridine with ortho-substituted phenacyl halides in ethanol has given 2-aryl-3H-pyrido[2,3-b][1,4]thiazines.For Communication XXVII, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1262–1265, September, 1973. Original article submitted March 15, 1972,     

A study of nitrogen- and sulfur-containing heterocycles

The reduction of -cyanoacylurethanes in an aqueous medium in the presence of hydrochlorides of aromatic amines and Raney nickel has given -arylaminoacryloyl-and -alkyl--arylaminoacryloylurethanes which have been converted by heating with 10 % aqueous caustic alkalis into 1-aryl-and 5-alkyl-1-aryluracils.For Communication X, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 8, pp. 1088–1091, August, 1970.     

Luminescence of some sulfur-containing heterocycles and their sulfones

The luminescence spectra (of crystals and toluene solutions) and the absolute quantum yields of the fluorescence of thianaphtheno[3, 2-b] -thianaphthene, tetraphenylthiophene, 2-phenylthianaphthene, and their sulfones have been measured. The oxidation of the sulfur heterocycles to the corresponding sulfones leads to a marked decrease in the intensity of their luminescence.     

Nitrogen-, oxygen-, and sulfur-containing heterocycles. 43. Synthesis and properties of 6-oxo-5H-pyrido[2,3-b][1,4]thiazines

It has previously been observed that the carbamide residue in 2-phenacyl-3-ureido- and 2-cyanomethylpyridine is readily cleaved on cyclization to pyridothiazines [1–4]. It was of interest to establish whether a similar process occurs when the carbonyl component is an -halo- or unsaturated acid. If this were the case, this reaction could be used to obtain 6-oxopyrido[2,3-b][1,4]thiazines.For communication 42, see [6].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 214–218, February, 1985.