Study of nitrogen- and sulfur-containing heterocycles. 54. Properties and conversions of pyrimido[4,5-<Emphasis Type="Italic">b</Emphasis>]-1,4-benzothiazepines. Synthesis of a novel heterocyclic system: Pyrimido[5,4-<Emphasis Type="Italic">c</Emphasis>]isoquinoline

We have studied some properties and conversions of pyrimido[4,5-b]-1,4-benzothiazepines: reduction, oxidation, reactions with nucleophilic reagents (methanol, hydrazine, hydroxylamine, o-methylhydroxylamine, and thiosemicarbazide). We have synthesized derivatives of a novel heterocyclic system: pyrimido[5,4-c]isoquinoline.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1863–1872, December, 2004.For Communication 53, see [1].     

Derivatives of condensed systems based on pyrimidine,pyrazine, and pyridine

Pyrimido[4,5-b]-1,4-thiazin-6-one and pyrimido[4,5-b]-1,5-thiazepin-6-one derivatives were obtained by reaction of 5-amino-6-chloropyrimidines with thioglycolic acid and 5-amino-6-mercaptopyrimidines with -bromopropionyl chloride. The IR spectra of the compounds are presented.See [1] for communication XXXV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1332–1335, October, 1977.     

Study of Nitrogen- and Sulfur-Containing Heterocycles. 57. Synthesis and Conversion of 4′-Substituted 5-(5-Amino-6-Pyrimidylthio)-2,2-Dimethyl-4,6-Dioxo-1,3-Dioxanes

By reaction of 4-substituted 5-amino-6-mercaptopyrimidines with 5-bromo-2,2-dimethyl-4,6-dioxo-1,3-dioxane, we have obtained 4′-substituted 5-(5-amino-6-pyrimidylthio)-2,2-dimethyl-4,6-dioxo-1,3-dioxanes. We have studied diazotization of these compounds by isoamyl nitrite. In the case of 4′-methoxy- and 4′-dimethylamino-substituted derivatives, we have obtained derivatives of novel heterocyclic systems: pyrimido[5,4-e][1,3,4]thiadiazine and pyrimido[5,4-e][1,3,4]thiadiazine-7-spiro-5′-1,3-dioxane, and in the case of the 4′-isopropylamino-substituted derivative we obtained 4-isopropyl-7-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-ylidene)-1,2,3-triazolo[5,4-d]pyrimidin-7-ylidene.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 613–623, April, 2005.     

Investigation of Nitrogen- and Sulfur-containing Heterocycles. 53. Reactions of 5-Amino-6-mercaptopyrimidines with Derivatives of p-Chloronitrobenzene. Synthesis of a New Heterocyclic System - Pyrimido[4,5-b]-1,4-benzothiazepine

A series of pyrimidyl aryl sulfides was obtained from the reaction of 5-amino-6-mercaptopyrimidines with derivatives of p-chloronitrobenzene containing carbonyl functional groups. The properties of these sulfides and methods of their cyclization into derivatives of a new tricylic system, pyrimido[4,5-b]-1,4-benzothiazepine, were studied.     

Derivatives of condensed pyrimidine,pyrazine, and pyridine systems

It is shown by means of IR, UV, and PMR spectroscopy that 5-amino-6-thio-1,6-dihydropyrimidines exist primarily in the thione form both in the crystalline state and in solution.See [1] for communication XXXIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 398–401, March, 1977.     

Nitrogen and sulfur containing heterocycles. 50. Synthesis and reactions of 6-oxopyrimido[4,5-b][1,4]thiazine-7-carboxylic acid derivatives

Reaction of 5-amino-6 mercaptopyrimidines with diethyl bromomalonate gave ethyl 6-oxopyrimido-[4,5-b][1,4]thiazine-7-carboxylates, from which there was synthesized a series of derivatives at the carboxyl group (amides, hydrazides, and, from the latter, urethanes). Desulfurization of the 6-oxopyrimidothiazine-7-carboxylic acid esters gave N-(pyrimidin-5-yl)monoamides of ethyl malonate.For communication 49 see [1].Center for Chemistry of Drugs—All-Russian Research Chemical-Pharmaceutical Institute, Moscow 119021, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 822–828, June, 1999.