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1.
A novel simple synthesis of 5-substituted-1,2,4-oxadiazole-3-carboxylates 5 from N-acylglycines 1 , which are transformed with DMF in the presence of phosphorus oxychloride into 2-substituted-4-dimethyl-aminomethyleneoxazol-5(4H)-ones 2 , followed by opening into 2-aroylamino-3-dimethylamino-propenoates 3 , and nitrosation to give the oximes 4 as intermediates, which cyclize spontaneously into 5-substituted-1,2,4-oxadiazole-3-carboxylates 5 . The compounds 2 can be transformed into 5 without isolation of 3 and 4 . 相似文献
2.
Wolfgang Stadlbauer Herbert Lutschounig Gerda Schindler Theo Witoszynskyj Thomas Kappe 《Journal of heterocyclic chemistry》1992,29(6):1535-1540
Nitration of 3-substituted-4-hydroxy-2(1H)-quinolones 1 with nitric acid leads either to 3-nitro- 2 or 3-hydroxyquinolinediones 3 , depending on the reaction conditions. 3-Substituted-3-hydroxyquinolinediones 3 are also obtained by oxidative hydroxylation with peracetic acid. Amination of 3-substituted-3-chloroquinolinediones 4 with ammonium hydroxide predominantly leads again to 3-substituted-3-hydroxyquinolinediones 3 , only in one case the 3-aminoquinolinedione 5 could be isolated. With morpholine or pyridine as amines the expected 3-aminoquinolinediones 6 and 7 were obtained. 相似文献
3.
A facile solid phase conversion of 2-chloro-3-cyano-4-substituted-1,4-dihydroquinolines to 3-cyano-4-substituted-3,4-dihydroquinolin-2(1H)-ones in almost quantitative yields and a novel synthesis of 2,3-dicarbomethoxy-2-hydroxycyclopenta[b]quinoline are described. 相似文献
4.
A series of 3,4-Dihydro-2-oxo-(3-substituted-2H-1,3-benzoxazin-4-yl)ureas (II, Table I) and 3,4-dihydro-2-oxo-(3-substituted-2H-1,3-benzoxazin-4-yl)thioureas (Table II) was prepared by treating 3,4-dihydro-4-hydroxy-3-substituted-2H-1,3-benzoxazin-2-ones with ureas and thioureas, respectively. In the presence of alcoholic alkali these compounds underwent transacylation to dihydro-6-(2-hydroxyaryl)-1,3,5-triazine-2,4-(1H,2H)diones (Table III) and their 4-thio analogues (Table IV). 相似文献
5.
6.
Douglas E. Murphy Peter S. Dragovich Benjamin K. Ayida Thomas M. Bertolini Lian-Sheng Li Frank Ruebsam Nebojsa S. Stankovic Zhongxiang Sun Jingjing Zhao Yuefen Zhou 《Tetrahedron letters》2008,49(5):811-815
A general procedure is described for the preparation of 6-substituted-5-hydroxy-3-oxo-2,3-dihydro-pyridazine-4-carboxylic acid ethyl esters (6-substituted-5-hydroxy-3(2H)-pyridazinone-4-carboxylic acid ethyl esters). These compounds are shown to undergo selective alkylation at the 2-position in moderate to good yields (19-77%) to afford 2,6-disubstituted-5-hydroxy-3-oxo-2,3-dihydro-pyridazine-4-carboxylic acid ethyl esters (2,6-disubstituted-5-hydroxy-3(2H)-pyridazinone-4-carboxylic acid ethyl esters). 相似文献
7.
Sergio Pinheiro Ronaldo C. da Silva Júnior José Walkimar de M. Carneiro O.A.C. Antunes 《Tetrahedron letters》2009,50(20):2402-962
Short stereoselective syntheses of both 5-substituted-4-amino-pyrrolidin-2-ones and 5-substituted-4-amino-3-pyrrolin-2-ones from natural α-amino acids are described. 相似文献
8.
Seiko Nan'ya Kaname Katsuraya Yoshio Ueno Etur
Maekawa 《Journal of heterocyclic chemistry》1988,25(1):109-112
5-Methyl- and 6-methyl-2-phenyl-2H-indazole-4,7-diones were condensed with 2-aminobenzenethiol or 6-substituted-3-aminopyridine-2(1H)thiones 4 to produce a new type of 5-methyl-2-phenyl-4H-pyrazolophenothiazin-4-ones or 8-substituted-7-aza-5-methyl-2-phenyl-4H-pyrazolophenothiazin-4-one derivatives. From 6-bromo-2,5-dimethyl-1,3-diphenyl-2H-isoindole-4,7-dione and 4 8-substituted-7-aza-2,5-dimethyl-1,3-diphenyl-4H-pyrrolophenothiazin-4-one derivatives were also prepared. 相似文献
9.
Starting from readily available 2-substituted-4-formylthiazoles and selenazoles, a series of 4-(2-aryl-4-selenazolyl)-1,2,3-selenadiazoles I and 4-(2-substituted-4-thiazolyl)-1,2,3-selenadiazoles II were prepared. Pyrolysis of compound II afforded (2-substituted-4-thiazolyl) acetylenes VII. Addition of potassium hydroxide pellets to an alcoholic solution of II gave 2-substituted-1,4-diselenafulvenes VIII. Decomposition of compound II with base followed by the addition of carbon disulfide gave 5-substituted 2-thioxo-1,3-thiaselenoles XI. 相似文献
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11.
1-substituted-5-benzoylamino-4-pyrazolecarboxamides(2)were prepared by the reaction of 1-substituted pyrazolo[3, 4-d]-oxazinone(1)with amines in benzene.The compound 2 was refluxed with excess LiAlH4 in a mixture of THF and ether, one of the two carbamoyl groups in the molecule 2 was reduced selectively.As the results, 1-substituted-5-benzylamino-4-pyrazolecarboxamides (3) were obtained.Compounds 3reacted with Cl2PPh-X, or P(NET2)3, producing the title compounds(4).The conditions of the reactions were studied. 相似文献
12.
A series of 5-substituted-4-amino-1,2,4-triazole-3-thioesters was synthesized by converting variously substituted organic acids successively into the corresponding esters, hydrazides, 5-substituted-1,3,4-oxadiazole-2-thiols, 5-substituted-1,2,4-triazole-2-thiols and 5-substituted-1,3,4-oxadiazole-2-thioesters. Finally the target compounds were obtained by refluxing 5-substituted-1,3,4-oxadiazole-2-thioesters in the presence of hydrazine hydrate and absolute alcohol. The structures of the synthesized compounds were established by physicochemical and spectroscopic methods. The synthesized compounds were evaluated for their in vitro antifungal activity. Some of the evaluated compounds possessed significant antifungal activity as compared to a terbinafine standard. 相似文献
13.
We have developed two efficient one-pot reactions to generate furo[3,2-c]coumarins and chlorofuro[3,2-c]coumarins through addition/cyclization/oxidation and chlorination. One cascade addition/cyclization/oxidation sequence of 1 with H(2)O in the presence of 20% CuCl as Lewis acid under an air atmosphere generated the 2-substituted-4 H-furo[3,2-c]chromen-4-one 2. Another sequence in the presence of 10% CuBr and excess CuCl(2) as the oxidant afforded the 3-chloro-2-substituted-4 H-furo[3,2- c]chromen-4-one 3. 相似文献
14.
The reaction of 1-substituted-3-methylpyrazol-5-ones 1 with alkyl chloroformates and calcium hydroxide in dioxane have been studied. With 1-phenyl-3-methylpyrazol-5-one, the isolated product was alkyl 3-methyl-5-oxo-1-phenylpyrazole-4-carboxylate 2 but with 1-alkyl-3-methylpyrazol-5-one formation of 1-alkyl-5-alkoxycarbonyloxy-3-methylpyrazole 3 was observed. Replacement of alkyl chloroformate by bis(alkoxythiocarbonyl) sulfide results in the formation of 4-alkoxythiocarbonyl derivatives 4 in low yield with both 1-substituted-3-methylpyrazol-5-ones. 相似文献
15.
16.
John S. Kiely Suchin Huang Lawrence E. Lesheski 《Journal of heterocyclic chemistry》1989,26(6):1675-1681
A general method for preparing 2-substituted-4-oxo-3-quinolinecarboxylic acids and 2-substituted-4-oxo-1,8-naphthyridine-3-carboxylic acids as new analogs in the quinolone class of antiinfectives has been developed. The reaction of a Grignard reagent in the presence of copper(I) iodide with the 4-oxo-3-quinolinecar-boxylic acid esters and 4-oxo-1,8-naphthyridine-3-carboxylic acid esters yields the desired 2-substituent. Re-introduction of the 2,3-double bond is effected by phenylselenation of the 3-position, oxidation to the selen-oxide, and in situ syn-elimisation. Depending on the degree of steric crowding between the 2-substituent and the 3-carboxylic acid group, hydrolysis of the ester to the carboxylic acid could be carried out under acidic or basic conditions. 相似文献
17.
18.
Raghu Prasad M Prashanth J Shilpa K Pran Kishore D 《Chemical & pharmaceutical bulletin》2007,55(4):557-560
A novel series of some novel 5-substituted-1,2,4-triazolo[4,3-c]8,9,10-trihydrocyclopenta/8,9,10,11,12-pentahydrocyclohepta[b]thieno[3,2-e]pyrimidin-3-thiones has been synthesized. The intermediates 4-chloro-2-substituted-5,6,7-trihydrocyclopenta/5,6,7,8,9-pentahydrocyclohepta[b]thieno[2,3-d]pyrimidines were prepared by warming 2-substituted-5,6,7-trihydrocyclopenta/5,6,7,8,9-pentahydrocyclohepta[b]thieno[2,3-d]pyrimidin-4[3H]-ones with oxalyl chloride. Thieno[2,3-d]pyrimidin-4[3H]-ones were prepared by a novel, microwave assisted, solvent free, synthetic route under basic conditions hitherto unreported in the literature from ortho amino ester of thiophene. The chloro derivatives, without further purification, were hydrazinated to yield 2-substituted-4-hydrazino-5,6,7-trihydrocyclopenta/5,6,7,8,9-pentahydrocyclohepta[b]thieno[2,3-d]pyrimidines. These compounds were cyclized with carbon disulphide to give the title compounds in quantitative yields. The final compounds were screened for antibacterial activity by Kirby Bauer's method using ampicillin as the standard against various gram positive and gram negative bacteria. All the compounds showed antibacterial activity comparable with the standard. 相似文献
19.
Frédérique Malbec René Milcent Patrick Vicart Anne Marie Bure 《Journal of heterocyclic chemistry》1984,21(6):1769-1774
Thirty new 2-substituted-4-amino-5-alkyl or aryl-2,4-dihydro-1,2,4-triazol-3-ones and ten 2-substituted-5-alkyl or aryl-4-(5-nitro-2-furfurylidene)amino-2,4-dihydro-1,2,4-triazol-3-ones were synthesized and characterised by their sharp melting points, elemental analysis, ir and 1H nmr spectra. These new derivatives of 5-nitro-2-furaldehyde were screened for their antibacterial activities. Most of the compounds showed good activity against one test organism, Staphylococcus aureus. For a few compounds, C.M.I. ranged from 4 to 8 μg/ml (higher results than nitrofurantoin). 相似文献
20.
A series of 3-substituted-2-thioxo-2,3-dihydroquinazolin-4(1H)-ones and 6-iodo-3-substituted-2-thioxo-2,3-dihydroquinazolin-4(1H)-ones were synthesized in choline chloride/urea deep eutectic solvent. Substituted 2-mercapto-4(3H)-quinazolinones were synthesized from anthranilic acid or 5-iodoanthranilic acid and appropriate isothiocyanates in good to excellent yields. Isolation of final product was easy and required no further purification. Synthesis of these compounds was rapid, selective, and catalyst free, while preparation of deep eutectic solvent was easy, components are readily available, cheap, and environmentally friendly. 相似文献