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1.
The method developed for the synthesis of thiazolo[3,2-a]pyridinium salts has been extended to the first synthesis of simple thiazolo[3,2-a]pyrimidinium, thiazolo[3,2-a]-pyrazinium and thiazolo[2, 3-b]benzo[d]thiazolium salts. No method could be found for the cyclization of 4′-bromo-2-(2-benzoxazolylthio)acetophenone to the thiazolo[2,3-b]-benzoxazolium system. 相似文献
2.
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
3.
E. V. Babaev A. A. Bush I. A. Orlova V. B. Rybakov I. Iwataki 《Russian Chemical Bulletin》2005,54(1):231-237
A new procedure was developed for the synthesis of 2-aminothiazolo[3,2-a]pyridinium salts 8 by the reaction of 2-halo-N-phenacylpyridinium salts with KSCN. The anion compositions of salts 8 were studied by ion chromatography. Acylation of salts 8 afforded representatives of the previously unknown bicyclic mesoionic thiazolo[3,2-a]pyridinium 2-imidate system 9. The three-dimensional structures of 2-amino-3-(p-bromobenzoyl)thiazolo[3,2-a]pyridinium thiocyanate and N-trifluoroacetyl-3-(p-nitrobenzoyl)thiazolo[3,2-a]pyridinium 2-imidate were established by X-ray diffraction analysis.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 226–232, January, 2005. 相似文献
4.
A series of novel tricyclic thiazolo[3,2-a]thiapyrano[4,3-d]pyrimidines and related oxa, aza and carbo analogs of general formula 1 were prepared by a convenient addition-cyclization reaction involving 2-amino-2-thiazoline ( 4 ) and bisarylidene ketones of formula 3. Some of these compounds demonstrated antiinflammatory activity. 相似文献
5.
Uro Urleb 《Journal of heterocyclic chemistry》1998,35(3):693-697
Heterocyclic isothiocyanates 1,5,9 , bearing an o-ester group were converted to thiourea derivatives 2a-c, 6a-b , and 10a-b , respectively, using β-aminoalcohols, and to the fused ring systems, e.g., thieno[3,2-d]pyrimidine 4a-b , pyrido[2,3-d]pyrimidine 8 , pteridine 11a , thiazolo[3,2-a]pyrido[2,3-d]pyrimidine 7a-b , and thiazolo[3,2-a]mieno[3,2-d]pyrirnidine 3a-c , derivatives. 相似文献
6.
I. V. Dyachenko R. I. Vas’kevich M. V. Vovk 《Russian Journal of Organic Chemistry》2014,50(2):263-270
2-[Allyl(propargyl)sulfanyl]pyrido[3,4-d]pyrimidin-4-ones at heating in polyphosphoric acid undergo an intramolecular cyclization with the formation of pyrido[4,3-e]thiazolo-[3,2-a]pyrimidin-5-ones of angular structure. Under similar conditions the cyclization of 2-(cinnamylsulfanyl)pyrido[3,4-d]-pyrimidin-4-one results in a linear pyrido[3′,4′:4,5]pyrimido-[2,1-b][1,3]thiazin-6-one. The iodocyclization of the same substrates affords the corresponding 9-(iodomethyl)(iodomethylidene)pyrido[4,3-e][1,3]thiazolo-[3,2-a]pyrimidin-5-ones and 3-iodopyrido[3′,4′:4,5]pyrimido[2,1-b][1,3]thiazin-6-one of angular structure. 9-(Iodomethyl)-8,9-dihydro-5H-pyrido[4,3-e][1,3]thiazolo[3,2-a]pyrimidin-5-one treated with sodium azide gave 9-(azidomethyl) derivative whose cyclization with substituted alkynes in the presence of copper compounds provided pyrido [4,3-e][1,3]thiazolo[3,2-a]pyrimidinylmethyltriazoles. 相似文献
7.
The reaction of 2-aminothiazoles with ethyl acetoacetate in acetic or polyphosphoric acid gave a series of 5H-[1,3]thiazolo[3,2-a]pyrimidin-5-one derivatives which were nitrated with a mixture of nitric and sulfuric acid to 6-nitro-5H-[1,3]thiazolo[3,2-a]pyrimidin-5-ones, and the latter were reduced to the corresponding amines. 相似文献
8.
A. D. Dyachenko S. M. Desenko V. D. Dyachenko A. N. Chernega 《Chemistry of Heterocyclic Compounds》2004,40(5):650-659
Partially hydrogenated thiazolo[3,2-a]pyridines have been synthesized by the interaction of functionally substituted ammonium di- and tetrahydropyridine-2-thiolates with bromocyclohexanone. The structure of 6,8-dicyano-3-hydroxy-5-oxo-1,3-tetramethylene-2,3,4,5,6,7-hexahydrospiro[thiazolo[3,2-a]pyridine-7,1'-(4'-methylcyclohexane)] has been determined by X-ray crystallography. 相似文献
9.
Babaev E. V. Rybakov V. B. Orlova I. A. Bush A. A. Maerle K. V. Nasonov A. F. 《Russian Chemical Bulletin》2004,53(1):176-180
A procedure was developed for the synthesis of representatives of the previously unknown bicyclic mesoionic thiazolo[3,2-a]pyridinium 2-thiolate system by the reaction of 2-X-N-phenacylpyridinium salts (X = Cl, SMe) with CS2 in the presence of Et3N. The three-dimensional structure of 3-(p-nitrobenzoyl)thiazolo[3,2-a]pyridinium 2-thiolate was established by X-ray diffraction analysis. 相似文献
10.
Iodination of 2-[allyl(methallyl)sulfanyl]-6-(trifluoromethyl)pyrimidin-4(3H)-ones was accompanied by cyclization to 2,3-dihydro[1,3]thiazolo[3,2-a]pyrimidin-4-ium triiodides. 3-(Iodomethyl)-3-methyl- 7-oxo-5-(trifluoromethyl)-2,3-dihydro[1,3]thiazolo[3,2-a]pyrimidin-4-ium triiodide was reduced with sodium iodide to 3,3-dimethyl-7-oxo-5-(trifluoromethyl)-2,3-dihydro[1,3]thiazolo[3,2-a]pyrimidin-4-ium iodide. 相似文献
11.
Natural abundance 13C NMR chemical shifts have been experimentally determined for a series of mesoionic thiazolo[3,2-a]pyrimidine-5,7-diones. The spectral data are compared with those of related mesoionic dihydrothiazolo[3,2-a]pyrimidine-5,7-diones and mesoionic 1,3,4-thiadiazolo[3,2-a]pyrimidine-5,7-diones. Resonable correlation between the observed 13C NMR chemical shifts and CNDO/2 total charge densities have been obtained for the different carbon atoms of 8-methylthiazolo[3,2-a]pyrimidine-5,7-dione. 相似文献
12.
L. M. Potikha A. R. Turelyk V. A. Kovtunenko A. V. Turov 《Chemistry of Heterocyclic Compounds》2010,46(2):223-231
A method for the synthesis of derivatives of [1, 3]thiazolo[3,2-a]pyridines, pyrido[2,1-b][1, 3]benzo-thiazole, [1, 3, 4]thiadiazolo[3,2-a]pyridine, and [1, 2, 4]triazolo[4,3-a]pyridine, which includes base initiated cyclization of quaternary azolium salts, formed by the interaction of (Z)-1,3-diaryl-4-bromo-2-buten-1-ones with 1-alkyl-1H-1,2,4-triazoles, 4-methyl-1,3-thiazole, 1,3-benzothiazole, and N-phenyl-1,3,4-thiadiazole-2-amine.
Derivatives of 2-chloroimidazo[1,2-a]pyridine were obtained when 5-chloro-1-methyl-1H-imidazole was used. 相似文献
13.
A new and efficient method for the synthesis of hitherto unreported spiro[benzo[4,5]thiazolo[3,2-a]chromeno[2,3-d]pyrimidine-14,3′-indoline]-1,2′,13(2H)-triones was developed via the Domino Knoevenagel condensation–Michael addition–intermolecular cyclization sequences of isatin derivatives, cyclohexane-1,3-diones, and 2-hydroxy-4H-benzo[4,5]thiazolo[3,2-a]pyrimidin-4-ones, employing 12-tungstophosphoric acid (H3PW12O40) as an effective and inexpensive catalyst. 相似文献
14.
Themolysis of naphth[1,2-d]imidazo[2,1-b]thiazole-2,3-dione ( 1 ) in dimethylformamide gave an intermediate 2-isocyanatonaphtho[1,2-d]thiazole ( 2 ), which underwent [4 + 4] cyclodimerization to yield dinaphtho-[1″,2″:4,5;1′″,2′″:4′,5′]dithiazolo[3,2-a:3′,2′-e]-1,3,5,7-tetrazocine-9,19-dione ( 3 ). The possible [4 + 2] cycloadduct, 3-(2-naphtho-[1,2-d]-thiazolyl)naphtho[1′,2′:4,5]thiazolo[3,2-a]-1,3,5-triazine-2,4-dione ( 4 ), an usual dimer type of heterocyclic isocyanates was not produced. Discrimination between the two isomers was established on the basis of spectral analyses. 相似文献
15.
Nehal A. Hamdy Hatem A. Abdel-Aziz Ahmad M. Farag Issa M. I. Fakhr 《Monatshefte für Chemie / Chemical Monthly》2007,60(4):1001-1010
3-(3-Methylthiazolo[3,2-a]benzimidazol-2-yl)-3-oxopropionitrile was synthesized by refluxing ethyl 3-methylthiazolo[3,2-a]benzimidazole-2-carboxylate, acetonitrile, and sodium hydride. Treatment of 3-(3-methylthiazolo[3,2-a]benzimidazol-2-yl)-3-oxopropionitrile with phenyl isothiocyanate, in the presence of KOH, furnished the corresponding potassium
salt which was converted into thioacetanilide derivative upon neutralization. The thioacetanilide derivative reacts with α-chloroacetylacetone
and ethyl α-chloroacetoacetate to give the 1,3-thiazole derivatives, while the reaction of the'thioacetanilide derivative
with hydrazonyl chlorides gave 1,3,4-thiadiazole derivatives. On the other hand, 3-(3-methylthiazolo[3,2-a]benzimidazol-2-yl)-3-oxopropionitrile reacted with the diazonium salt of both 3-phenyl-5-amino-(1H)-pyrazole and 5-amino-l,2,4-(1H)-triazole to afford the corresponding hydrazones. The latter hydrazones underwent an intramolecular cyclization upon boiling
in pyridine to give pyrazolo[5,1-c]-1,2,4-triazine and 1,2,4-triazolo[5,1-c]-1,2,4-triazine derivatives. Moreover, the behavior of thiazolo[3,2-a]benzimidazol-3(2H)-one towards phenyl isothiocyanate followed by the reaction with α-chloroketones or hydrazonyl chlorides was investigated.
Some of the latter compounds exhibited moderate effects against some bacterial and fungal species. 相似文献
16.
Dyachenko V. D. Dyachenko A. D. Chernega A. N. 《Russian Journal of Organic Chemistry》2004,40(3):397-406
Cyclopentylidene- and cyclohexylidene(cyano)acetamides reacted with malononitrile and cyano-(thioacetamide) according to the Michael pattern with exchange of the methylene components to give substituted 1-amino-2,6,6-tricyano-1,3-cyclohexadienes and thieno[2,3-d]pyrimidine-4(3H)-thiones. Condensation of cyclopentylidene- and cyclohexylidene(cyano)acetamide with 1,3-dicarbonyl compounds afforded 4,6-di-methyl-3-cyanopyridine-2(1H)-thione and morpholinium 4-methyl-6-oxo-3-cyano-1,6-dihydropyridine-2-thiolate which were converted into substituted 2-alkylsulfanylpyridines, thieno[2,3-b]pyridines, thiazolo[3,2-a]pyridine, and 2H-[1,3]thiazino[3,2-a]pyridine. 相似文献
17.
E. V. Nosova G. N. Lipunova A. A. Laeva V. N. Charushin 《Russian Journal of Organic Chemistry》2005,41(11):1671-1677
Reactions of 2-aminothiazole, derivatives of 2-aminobenzothiazole and 2-aminobenzoimidazole with polyfluorobenzoyl chlorides gave rise to acylation products that at heating in the diphenyl ether formed fluoro-containing derivatives of thiazolo[3,2-a]-, benzothiazolo[3,2-a]-, and benzimidazo[3,2-a]quinazolinone. 相似文献
18.
Nehal A. Hamdy Hatem A. Abdel-Aziz Ahmad M. Farag Issa M. I. Fakhr 《Monatshefte für Chemie / Chemical Monthly》2007,138(10):1001-1010
Summary. 3-(3-Methylthiazolo[3,2-a]benzimidazol-2-yl)-3-oxopropionitrile was synthesized by refluxing ethyl 3-methylthiazolo[3,2-a]benzimidazole-2-carboxylate, acetonitrile, and sodium hydride. Treatment of 3-(3-methylthiazolo[3,2-a]benzimidazol-2-yl)-3-oxopropionitrile with phenyl isothiocyanate, in the presence of KOH, furnished the corresponding potassium
salt which was converted into thioacetanilide derivative upon neutralization. The thioacetanilide derivative reacts with α-chloroacetylacetone
and ethyl α-chloroacetoacetate to give the 1,3-thiazole derivatives, while the reaction of the'thioacetanilide derivative
with hydrazonyl chlorides gave 1,3,4-thiadiazole derivatives. On the other hand, 3-(3-methylthiazolo[3,2-a]benzimidazol-2-yl)-3-oxopropionitrile reacted with the diazonium salt of both 3-phenyl-5-amino-(1H)-pyrazole and 5-amino-l,2,4-(1H)-triazole to afford the corresponding hydrazones. The latter hydrazones underwent an intramolecular cyclization upon boiling
in pyridine to give pyrazolo[5,1-c]-1,2,4-triazine and 1,2,4-triazolo[5,1-c]-1,2,4-triazine derivatives. Moreover, the behavior of thiazolo[3,2-a]benzimidazol-3(2H)-one towards phenyl isothiocyanate followed by the reaction with α-chloroketones or hydrazonyl chlorides was investigated.
Some of the latter compounds exhibited moderate effects against some bacterial and fungal species. 相似文献
19.
2-Hydroxy-4H-benzo[4,5]thiazolo[3,2-a]pyrimidin-4-one 2a and 7-hydroxy-5H-thiazolo[3,2-a]pyrimidin-5-one 2b, were obtained in high yields under mild conditions from the cyclization reactions of bis-(2,4,6-trichlorophenyl) malonate and 2-aminobenzothiazole or 2-aminothiazole, respectively. A new class of compounds, 2,3-dihydro-4H-benzo[4,5]thiazolo[3,2-a]furo[2,3-d]pyrimidin-4-ones and 6,7-dihydro-5H-furo[2,3-d]thiazolo[3,2-a]pyrimidin-5-ones, were synthesized via the microwave assisted radical addition of compounds 2a and 2b to various alkenes using manganese(III) acetate. A preliminary acetylcholine esterase (AchE) inhibition test of compound 4e showed excellent (92%) inhibitory potential, comparable with the standard drug Donapezil®. 相似文献
20.
Branko Stanovnik Henry Van De Bovenkamp Jurij Svete Ale Hvala Igor Simoni
Miha Tiler 《Journal of heterocyclic chemistry》1990,27(2):359-361
Methyl 2-benzoylamino-3-dimethylaminopropenoate ( 2 ) was introduced as a new reagent for the preparation of fused pyrimidinones 4 from heterocyclic α-amino compounds in acetic acid. In this manner, derivatives of pyrido[1,2-a]pyrimidine 4a,b,f , pyrimido[1,2-b]pyridazine 4g , pyrimido[1,2-c]pyrimidine 4j , pyrazino[1,2-a]pyrimidine 4k , thiazolo[2,3-b]pyrimidine 41 , pyrazolo[1,5-a]pyrimidine 4m , and 1,2,4-triazolo-[1,5-a]pyrimidine 4n were prepared. 相似文献