共查询到20条相似文献,搜索用时 0 毫秒
1.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, p. 1148, August, 1992. 相似文献
2.
3.
S. S. Shukurov M. A. Kukaniev I. M. Nasyrov K. S. Zakharov R. A. Karakhanov 《Russian Chemical Bulletin》1993,42(11):1871-1874
The reactions of 2-amino-5-mercapto-(or 2,5-dimercapto)-1,3,4-thiadiazoles with 2-bromo-7-methyl-5-oxo-5H-1, 3,4-thiadiazolo[3, 2-a]pyrimidine to give the corresponding sulfides have been studied. The possibility of S-alkylation and addition of quinone at the free mercapto group in the 1,3,4-thiadiazole ring has been shown. The reactions at the amino group with benzoyl chloride and chloroformates have been investigated. The conditions of cyciodehydration at the amino group with ethyl acetoacetate and bromination of the pyrimidine fragment of 7-methyl-5-oxo-5H-1,3,4-thiadiazolo[3,2-a]pyrimidine have been found.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1954–1957, November, 1993 相似文献
4.
S. Sh. Shukurov M. A. Kukaniev M. I. Nasyrov K. S. Zakharov R. A. Karakhanov 《Russian Chemical Bulletin》1994,43(5):854-856
The reactions of 2-chloromethyl-7-methyl-5H-1,3,4-thiadiazolo[3,2-a]pyrimidin-5-one withtert-butyl hypochlorite and molecular bromine and the replacement of the chlorine atom in the chloromethyl group through the action of piperidine and morpholine were investigated.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 908–910, May, 1994. 相似文献
5.
S. Sh. Shukurov D. A. Artykova M. A. Kukaniev K. S. Zakharov I. M. Nasyrov D. M. Osimov 《Russian Chemical Bulletin》1994,43(8):1402-1404
In the reaction with carbon disulfide, 2-amino-7-methyl-5-oxo-5H-1,3,4-thiadiazolo[3,2-a]pyrimidine (1) forms the alkaline salts of substituted dithiocarbamic or iminodithiocarbonic acids depending on the molar ratio between1, CS2, and the alkali. The alkylation of these salts leads to the esters ofN-(7-methyl-5-oxo-5H-1,3,4-thiadiazolo[3,2-a]pyrimidine-2-yl)dithiocarbamic (2) and diesters of (7-methyl-5-oxo-5H-1,3,4-thiadiazolo[3,2-a]pyrimidine-2-yl)iminodithiocarbonic acids (3). The synthesis of asymmetric diesters3 may be fulfilled based on monoesters2.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 14–14, August, 1994. 相似文献
6.
M. A. Kukaniev U. Nurov S. Sh. Shukurov Yu. Khodzhibaev 《Russian Chemical Bulletin》1999,48(6):1143-1145
Convenient procedures were developed for the preparation of new 2-R-thio and 2-amino derivatives of 7-methyl-6-nitro-5-oxo-5H-1,3,4-thiadiazolo[3,2-a]pyrimidines and products of their condensation with aldehydes. 相似文献
7.
M. A. Kukaniev S. Sh. Shukurov Yu. Khodzhibaev N. Kurbonova S. G. Bandaev 《Russian Chemical Bulletin》1998,47(11):2300-2301
2-Ethoxycarbonylmethyl-7-methyl-1,3,4-thiadiazolo[3,2-a]pyrimidin-5(5H)-one containing the active methylene group reacts easily with carbon disulfide and phenyl isothiocyanate in the presence
of sodium hydride. Further alkylation of the reaction product by alkyl halides results in the formation of the corresponding
1,3,4-thiadiazolo[3,2-a]pyrimidine derivatives containing a ketene dithioacetal fragment.
Deceased.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2371–2373, November, 1998. 相似文献
8.
S. Sh. Shukurov D. A. Artykova I. M. Nasyrov K. S. Zakharov R. A. Karakhanov 《Russian Chemical Bulletin》1993,42(1):201-202
Synthesis of the title compound is described and its reaction with bromine is studied. This involves oxidation of the hydrazine moiety and sequential bromination of the benzene and thiadiazolopyrimidine nuclei to give, respectively, 2-(4-bromophenylazo)-7-methyl-5-oxo-5H-1, 3,4-thiadiazolo[3,2-a]pyrimidine and 6-bromo-2-(4-bromophenylazo)-7-methyl-5-oxo-5H-1, 3,4-thiadiazolo[3,2-a]pyrimidine.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 219–220, January, 1993. 相似文献
9.
S. S. Shukurov M. A. Kukaniev I. M. Nasyrov K. S. Zakharo R. A. Karakhanov 《Russian Chemical Bulletin》1993,42(11):1874-1878
Reactions of 2-bromo-7-methyl-5-oxo-5H-1,3,4-thiadiazolo[3,2-a]pyrimidine with sodium derivatives of pentane-2,4-dione, malonodinitrile, Meldrum acid, acetoacetic, cyanoacetic and malonic esters have been shown to give the respective substituted derivatives. Azinyl-ylidene tautomerism has been found to be characteristic of these compounds, the latter existing mainly in the ylidene form. The acid hydrolysis of pentane-2, 5-dione and cyanoacetic and malonic esters derivatives has been investigated.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1957–1961, November, 1993 相似文献
10.
11.
S. Sh. Shukurov D. A. Artykova K. S. Zakharov M. A. Kukaniev D. M. Osimov 《Chemistry of Heterocyclic Compounds》1994,30(4):495-497
The reaction of 2-hydrazino-7-methyl-5-ozo-5H-1,3,4-thiadiazolo[3,2-a]pyrimidine with carbon disulfide leads to the formation of hydrazinecarbodithioates and their cyclization products.V. I. Nikitina Institute of Chemistry, Academy of Sciences of the Republic of Tadzikistan, Dushanbe 734063. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 560–562, April, 1994. Original article submitted December 13, 1993. 相似文献
12.
Reaction of 2-substituted 5-imino-7-oxo-1,3,4-thiadiazolo[3,2-a]pyrimidines with pentane-2,4-dione in polyphosphoric acid yields 9-oxo-1,3,4-thiadiazolo[3,2-a]pyrido[3,2-e]pyrimidines.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2037–2038, October, 1995.The authors are grateful to V. A. Dorokhov for the skilled preparation of the paper for publication. 相似文献
13.
7-Oxo-7H-[1,3,4]thiadiazolo[3,2-a]pyrimidine-5-carboxylate derivatives are biologically and pharmacologically useful heterocycles. An efficient synthetic methodology for this class of compounds was developed through catalyst-free, one-pot reactions between 2-aminothiadiazoles and dimethyl acetylenedicarboxylate (DMAD) in THF with the aid of ultrasound irradiation. The reactions show applicability to a wide range of substrates and high regioselectivity for the “7-one” products over their “5-one” isomers. Detailed reaction mechanisms were mapped out by theoretical modeling analysis based on density functional theory (DFT) calculations. Mechanistic studies indicate that the favored reaction pathway involves a sequence of hydrogen-bond directed Michael addition, synergistic proton transfer/five-membered ring opening, and intramolecular cyano hetero-Diels-Alder reactions. 相似文献
14.
15.
Russian Journal of Organic Chemistry - An efficient synthetic approach to new fluorine-containing [1,3,4]thiadiazolo[3,2-a]quinazolin-5-ones has been developed on the basis of intramolecular... 相似文献
16.
V. N. Britsun A. N. Esipenko M. O. Lozinskii 《Chemistry of Heterocyclic Compounds》2006,42(5):693-697
3-Amino-2-thioxo-1,2,3,4-tetrahydroquinazolin-4-ones were converted into 2-aryl-5H-[1,3,4]thiadiazolo[2,3-b]quinazolin-5-ones
on treatment with carboxylic acids and POCl3. 3-Arylmethylidenamino-2-thioxo-1,2,3,4-tetrahydroquinazolin-4-ones also cyclized to 2-aryl-5H-[1,3,4]thiadiazolo[2,3-b]quinazolin-5-ones
when oxidized with potassium chlorate in acetic acid, but on heating they were deaminated to give 2-thioxo-1,2,3,4-tetrahydroquinazolin-4-one
and aryl nitriles.
__________
Translated from Khimiya Geteotsiklicheskikh Soedinenii, No. 5, 787–791, May, 2006. 相似文献
17.
The 70 eV electron impact mass spectra of some 1,3,4-thiadiazolo[3,2-a]pyrimidin-7-one and isomeric-5-one derivatives are discussed with the aid of defocused metastable spectra and exact mass measurements. The compounds are shown to be very stable to electron impact and ring contraction reactions are in most cases the characterstic fragmentations. Most importantly, the 7-one derivatives fragment by a retro-Diels–Alder process which does not occur in the 5-one isomers. This provides a diagnostic tool for differentiation between the isomers and for the unequivocal assignment of the structure. 相似文献
18.
Formic acid-phosphorus pentoxide was effective for the preparation of 5,7-dimethyl[1,3,4]thiadiazolo- and -[1,3]thiazolo[3,2-a]pyrimidin-4-ium salts. Further, the pyrimidine ring transformation and the isocyanation of 5imino-6H-[1,3,4]thiadiazolo- and -[1,3]thiazolo[3,2-a]pyrimidin-7-ones were carried out in the presence of formic acid and triethyl orthoformate, respectively. 相似文献
19.
S. Sh. Shukurov M. A. Kukaniev V. M. Bobogaribov S. S. Sabirov 《Chemistry of Heterocyclic Compounds》1993,29(8):981-981
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1146–1147, August, 1993. 相似文献