5-甲基-3-喹喔啉-2-基-4-乙氧羰基异噁唑及其衍生物的合成

以α-氯代喹喔啉-2-甲醛肟(3)与乙酰乙酸乙酯的钠盐经1,3-偶极环加成制得关键中间体5-甲基-3-喹喔啉-2-基-4-乙氧羰基异噁唑(4). 以化合物4为原料在不同条件下, 合成了一系列新的1,3,4-噁二唑啉(7), 1,2,4-均三唑的Mannich碱衍生物10a～10f, 11a～11f, 12a～12f. 化合物的结构经元素分析, IR, 1H NMR和MS确认, 并对其波谱性质进行了讨论.     

Synthesis of 3-(quinoxalin-2-yl)-2H-chromen-2-ones under microwave irradiation

Abstract  A facile procedure for the synthesis of quinoxalines is being reported starting from 3-(2-bromoacetyl)coumarins or 3-(2-bromobutanoyl)coumarins and substituted o-phenylenediamines. The reactions were carried out under catalyst-free and microwave irradiation conditions producing the title compounds in moderate to excellent yields in a short time with easy workup. The structures of all new compounds have been confirmed on the basis of their IR, ¹H NMR, ¹³C NMR, and HRMS data. Graphical Abstract        

3-(α-azidoalkyl)quinoxalin-2(1H)-ones and related alkylquinoxalinyl ketones

A convenient method has been developed for the synthesis of 3-alkanoyl-and 3-benzoyl-2-oxo-1,2-dihydroquinoxalines from the corresponding 3-(α-azidoalkyl)quinoxalines using acetic acid. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 574–577, 2007.     

Diels-alder reaction of (E)-4-(2-nitroethenyl)-1H-imidazoles and methyl (E)-3-(1-imidazol-4-yl)propenoates

Diels-Alder reaction of methyl (E)-3-(1H-imidazol-4-yl)propenoates 2, 3a-c and (E)4-(2-nitroethenyl)-1H-imidazoles 3d,e with 2,3-dimethyl-1,3-butadiene, cyclopentadiene, and cyclohexa-1,3-diene gave the corresponding cycloadducts 6–9 .     

Synthesis of 1-[2-(1H-Indol-3-yl)ethyl]-4-acetyl-3-hydroxy-5-phenyl-1H-pyrrol-2(5H)-ones

Russian Journal of General Chemistry - 1-[2-(1H-indol-3-yl)ethyl]-4-acetyl-3-hydroxy-5-phenyl-1H-pyrrole-2(5H)-ones were synthesized by the short heating of a mixture of tryptamine, aromatic...     

N-[2-(1H-吲哚-3)乙基]-2-乙酰噻唑-4-甲酰胺及其类似物的合成

N-[2-(1H-吲哚-3)乙基]-2-乙酰噻唑-4-甲酰胺是最近从海洋细菌中分离得到的一种新型的天然杀藻剂, 以D-丙氨酸为原料合成了该化合物, 并用类似的方法首次合成了它的类似物2, 3和4. 其关键步骤为通过将取代的4-噻唑甲酸制成混酐与色胺连接的偶联反应. 各中间体都通过¹H NMR和¹³C NMR得到证实. 最终产品通过¹H NMR, ¹³C NMR和HRMS证实, 与文献所报道相一致.     

Synthesis and mass spectral studies of 1-[5-chloro-1-substituted-2(1H)-pyrazin-2-on-3-yl]-5-aryl-3-methylpyrazoles

Sixteen new 1-[5-chloro-1-substituted-2(1H)-pyrazin-2-on-3-yl]-5-aryl-3-methylpyrazoles V have been synthesized by condensation of 5-chloro-1-substituted-3-hydrazino-2(1H)-pyrazin-2-ones III and 1-aryl-1,3-butanediones IV in dry 1,4-dioxane. The general mass spectral fragmentation mode of these compounds has been studied.     

Concise route to a series of novel 3-(tetrazol-5-yl)quinoxalin-2(1H)-ones

This report presents a novel three step solution phase protocol to synthesize 3-(tetrazol-5-yl)quinoxalin-2(1H)-ones. The strategy utilizes ethyl glyoxalate and mono-N-Boc-protected-o-phenylenediamine derivatives in the Ugi-Azide multi-component reaction (MCR) to generate a unique 1,5-disubstituted tetrazole. Subsequent acid treatment stimulates a simultaneous Boc deprotection and intramolecular cyclization leading to bis-3,4-dihydroquinoxalinone tetrazoles. Direct oxidation using a stable solid-phase radical catalyst (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) with ceric ammonium nitrate (CAN) in catalytic fashion initiating aerobic oxidation, completes the entire procedure to generate a series of original unique bis-quinoxalinone tetrazoles. The method was also expanded to produce a bis-benzodiazepine tetrazole.     

Synthesis of 3-(2-benzothiazolylthio)propanenitrile and related products

The reaction of 2-mercaptobenzothiazole, 2-mercaptobenzoxazole or 5-chloro-2-mercaptobenzothiazole with either acrylonitrile or acrylamide under basic conditions afforded the N-cyanoethylated products 1, 2 and 3 or the N-amidoethylated products 4, 5 and 6 , respectively. The reaction of the sodium salts of the same thiazolethiols with 3-chloropropionitrile furnished a mixture containing the N-cyanoethylated products 1, 2 and 3 and the unknown S-cyanoethylated products 7, 8 and 9 , respectively. Whereas, substituting 3-chloropropionamide for 3- chloropropionitrile in the same reaction gave only the S-substituted products 10, 11 , and 12 , respectively. The treatment of 10, 11 or 12 with phosphorus oxychloride or thionyl chloride in DMF afforded 7, 8 and 9 in excellent yields. Possible mechanisms and supporting nmr data are discussed.     

Kinetics and mechanism of ring transformation of S-[1-(4-methoxyphenyl)pyrrolidin-2-on-3-yl]isothiuronium bromide to 2-methylimino-5-[2-(4-methoxyphenylamino)ethyl]thiazolidin-4-one

The kinetics and mechanism of transformation reaction of S-[1-(4- methoxyphenyl)pyrrolidin-2-one-3-yl]-N-methyl-isothiuronium bromide into 2-methylimino-5-[2-(4-methoxyphenylamino) ethyl)]thiazolidin-4-one have been studied in aqueous solutions of amine buffers (pH 8.1-11.5) and sodium hydroxide solutions (0.005-0.5 mol l-1) at 25 degrees C and at I = 1 mol l-1 at pseudo-first-order reaction conditions. The kinetics observed shows that the transformation reaction is subject to general base, general acid, and hydroxide-ion catalyses. The rate-limiting step of transformation is the splitting-off a proton from the tetrahedral intermediate In. The value of pKa for S-[1-(4-methoxyphenyl)- pyrrolidin-2-one-3-yl]-N-methylisothiuronium bromide has been determined from the kinetic data (pKa = 8.75 +/- 0.10) and by potentiometric titration (pKa = 8.90 +/- 0.05). With increasing pKa value of the acid buffer component, the value of Br?nsted coefficient beta gradually decreases from about 0.7 to almost zero. The value of pKa approximately 10 for the intermediate to base-catalysed transformation has been found from this dependence. In the N-methylpyrrolidine and triethylamine buffers, the rate-limiting step of transformation is changed into ring opening of In-, and the general-base-catalysed reaction changes into a specific-base-catalysed one.     

Synthesis and Bioactivity of 5-Aryl-4-acyl-3-hydroxy-1-[2-(imidazolyl-3-yl)ethyl]3-pyrroline-2-ones

Russian Journal of General Chemistry - 5-Aryl-4-acyl-3-hydroxy-1-[2-(imidazolyl-3-yl)ethyl]-3-pyrroline-2-ones were synthesized by three-component reaction of methyl dioxobutanoates with aromatic...     

Synthesis of Derivatives of 4-Hydroxy-2-methyl-3-[2-(5-mercapto-1H-1,2,4-triazol-3-yl)ethyl]quinoline and 2-[2-(4-Hydroxy-2-methyl-3-quinolyl)ethyl]-4H-3,1-benzoxazin-4-one

From 4-hydroxy-2-methylquinoline-3-propionyl chlorides hydrochlorides the corresponding thiosemicarbazides were synthesized. The cyclization of the latter both in alkaline and acidic media furnished 4-hydroxy-2-methyl-3-[2-(5-mercapto-1H-1,2,4-triazol-3-yl)ethyl]quinolines. The reaction of the above propionyl chlorides with anthranilic acid afforded the corresponding 2-[2-(4-hydroxy-2-methyl-3-quinolyl)ethyl]-4H-3,1-benzoxazin-4-ones.     

Synthesis of N-Substituted Derivatives of 3-(1,4-Benzodioxan-2-yl)-4-phenyl-1,2,4-triazole-5(4H)-thiones

Russian Journal of Organic Chemistry - The addition of 5-(1,4-benzodioxan-2-yl)-4-phenyl-4H-1,2,4-triazole-3-thiol to the C=C double bond of acrylonitrile, acrylamide, and ethyl acrylate afforded...     

Synthesis of 5-fluoro-2-methyl-3-(2-trifluoromethyl-1,3,4-thiadiazol-5-yl)-4(3H)-quinazolinone and related compounds with potential antiviral and anticancer activity

The synthesis of ten new substituted 1,3,4-thiadiazolyl-4(3H)-quinazolinones 8–11, 13, 17 , and 20–23 is reported. Compounds 8–11 were prepared by condensation of 5-fluoro-2-methyl-3,1-benzoxazin-4-one (3) and 5-substituted 2-amino-1,3,4-thiadiazoles 4–7. Compound 13 was obtained by condensation of 5-fluoro-2-methyl-3,1-benzoxazin-4-one (3) with DL-α-amino-?-caprolactam (12) . Compound 17 was synthesized by condensation of 6-bromo-2-methyl-3,1-benzoxazin-4-one (16) and 2-amino-5-t-butyl-1,3,4-thiadiazole (5) . Compounds 20–23 were obtained by condensation of 5-chloro-6,8-dibromo-2-methyl-3,1-benzoxazin-4-one (19) and 5-substituted 2-amino-1,3,4-thiadiazoles 4–7, respectively. The substituted 3,1-benzoxazin-4-ones 3, 16, and 19 were obtained in good yield by refluxing the appropriate anthranilic acid, 1,15 , and 18 with acetic anhydride (2) .     

Synthesis and Properties of 1-(Alkylsulfanyl)-3-(morpholin-4-yl)propan-2-yl Arylcarbamates and Arylcarbamothioates

Russian Journal of Organic Chemistry - New arylcarbamates and arylcarbamothioates were synthesized by reactions of 1-(alkylsulfanyl)-3-(morpholin-4-yl)propan-2-ols with aryl isocyanates and aryl...     

Synthesis of ethyl 4-(1,2,3-thiadiazol-4-yl)-5-(bromomethyl)furan-2-carboxylate and its reactions with nucleophiles

By cyclization of carboethoxyhydrazone of ethyl 4-acetyl-5-methylfuran-2-carboxylate under the conditions of Hurd–Mori reaction ethyl 4-(1,2,3-thiadiazol-4-yl)-5-methylfuran-2-carboxylate was synthesized. The ester obtained was brominated with N-bromosuccinimide at the methyl group in the furan ring. This bromide reacts with various N-, S-, O-, and P-nucleophiles to form the corresponding substitution products. Furylthiadiazole fragment remains stable in the course of these transformations.