哒嗪酮-类肟醚菊酯衍生物的合成研究

从2-叔丁基-4,5-二氯哒嗪酮出发,以两种方法合成了中间体2-叔丁基-4-氯-5-(4-溴甲基苯氧)哒嗪酮(3)。3与肟反应合成了含哒嗪酮的苄基肟醚类化合物4a～4l。在相转移催化条件下,3与芳香醛肟反应得到单一的产物4,与芳香酮肟反应则生成4和5的混合物。文中讨论了反应物的空间效应、亲核试剂对该反应区域选择性的影响,并论证了产物的构型。     

糖苷合成研究(ⅩⅩⅠ)2-N-(β-D-吡喃葡萄糖-1-基)-6-(4-卤代苯基)-3-哒嗪酮的合成

在相转移催化条件下,2,3,4,6-四-O-乙酰基-1-溴-1-脱氧-α-D-吡喃葡萄糖1与6-(4-卤代苯基)-3(2H)-哒嗪酮2反应,合成了4种新的哒嗪酮葡萄糖苷3;然后用干燥的氨气在0～-5 ℃下处理,得相应的2-N-(β-D-吡喃葡萄糖-1-基)-6-(4-卤代苯基)-3-哒嗪酮4. 这些化合物的结构经IR、1H NMR、13C NMR及元素分析所证实.     

4-卤-5-(4-甲基-2H-1-苯并-2-吡喃酮-7-氧基)-2-取代-3(2H)-哒嗪酮衍生物的合成和生物活性研究

通过4,5-二氯(溴)-3(2H)-哒嗪酮与7-羟基-4-甲基香豆素在CH3CN/K2CO3体系下的缩合反应,将具有生物活性的哒嗪酮环引入到苯并吡喃酮结构中,设计、合成了9个含哒嗪酮环的香豆素类化合物,其中8个为新化合物.所有化合物的结构均经NMR,MS和元素分析确证.初步生物活性测试结果表明:化合物4-氯-5-(4-甲基-2H-1-苯并吡喃-2-酮-7-氧基)-2-(4-硝基苯基)-3(2H)-哒嗪酮对黄瓜根部具有一定的抑制作用.     

肟的无气味硫缩醛/酮化反应

探讨了以无气味且稳定的α-羰基二硫缩烯酮(1)作为代硫醇试剂的肟(2)的硫缩醛/酮化反应. 在乙酰氯-乙醇(体积分数95%)或4-十二烷基苯磺酸(DBSA)-水体系中及回流条件下, 化合物1与肟2能有效地进行硫缩醛/酮化反应. 反应过程中未闻到硫醇的恶臭气味.     

哒嗪酮的乙酰胺类化合物的合成及生物活性

2-叔丁基-4-氯-5-羟基-哒嗪-3(2H)-酮(3)与相应的N-烷基或N,N-二烷基氯乙酰胺(4a-4l)反应,合成了2-叔丁基-5-[(N-烷基或N,N-二烷基乙酰胺)氧基]-4-氯-哒嗪-3(2H)-酮(1a-1l),生物活性测定结果表明部分化合物(1a-1l)具有杀虫活性。     

新型环己烯酮衍生物的合成

根据活性基团拼接原理,以烯草酮为先导化合物,通过修饰其肟醚位,引入具有除草活性的环苯草酮肟醚结构,设计并合成了一个新型的环己烯酮衍生物(7)。以对氯苯酚为原料,经取代、还原、卤代、肟醚化、水解等5步反应制得O-［2-(4-氯苯氧基)丙基］-羟胺盐酸盐(5); 5与5-［2-(乙硫基)丙基］-3-羟基-2-丙酰基-2-环己烯-1-酮反应合成了7,其结构经¹H NMR, ¹³C NMR, IR, ESI-MS和元素分析表征。     

2-芳基-5-(6-哒嗪酮-3-基)-1,3,4-噁二唑的合成

1,4,5,6-四氢-6-哒嗪酮-3-甲酰肼(1)和1,6-二氢-6-哒嗪酮-3-甲酰肼(2)与芳香醛反应得到相应的芳香醛腙3a～3g和5a～5g, 再将3a～3g, 5a～5g在溴的作用下, 合环得到一系列1,3,4-噁二唑的衍生物4a～4g和6a～6g. 化合物的结构经1H NMR, IR, MS和元素分析得以证实.     

3-O-(β-D-吡喃葡萄糖-1-基)-6-(4-卤代苯基)哒嗪的合成与表征

利用6-(4-卤代苯基)-3(2H)-哒嗪酮的银盐(2)与2,3,4,6-四-O-乙酰基-1-溴-1-脱氧-α-D-吡喃葡萄糖(3)发生Koenigs-knorr反应, 合成了3-O-(2,3,4,6-四-O-乙酰基-β-D-吡喃葡萄糖-1-基)-6-(4-卤代苯基)哒嗪(4),4用干燥的氨气在0℃～-5℃下处理脱乙酰基保护基得相应的3-O-(β-D-吡喃葡萄糖-1-基)-6-(4-卤代苯基)哒嗪(5).其结构经元素分析,IR及1H NMR证实.     

3-D-（β-D-吡喃葡萄糖-1-基）-6-（4-卤代苯基）哒嗪的合成与表征

利用6-(4-卤代苯基)-3(2H)-哒嗪酮的银盐(2)与2，3，4，6-四-O-乙酰基-1-溴-1-脱氧-α-D-吡喃葡萄糖(3)发生Koenig’s-knorr反应，合成了3-0-(2，3，4，6-四-O-乙酰基-β-D-吡喃葡萄糖-1-基)-6-(4-卤代苯基)哒嗪(4)，4用干燥的氨气在0℃～-5℃下处理脱乙酰基保护基得相应的3-O-(β-D-吡喃葡萄糖-1-基)-6-(4-卤代苯基)哒嗪(5)。其结构经元素分析，IR及1H NMR证实。     

5-氨基-5,6,7,8-四氢-2(1H)-喹啉酮的简便合成

改进了合成5-氨基-5,6,7,8-四氢-2(1H)喹啉酮(5)的方法。以环己二酮为原料,通过亚胺化,Michael反应-环化反应,成肟反应和碱性条件下镍铝合金催化还原共四步反应合成了5,总收率19.6%,其结构经1HNMR,IR和MS确证。     

Syntheses and anti-inflammatory activity of novel oximes and O-acyloximes.

Novel oximes were prepared from the corresponding aldehyde or ketone in the usual way, and a number of oxime esters, O-lauroyl, O-2-pyridinecarbonyl, O-nicotinoyl, and O-isonicotinoyl oximes were synthesized by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDCI)-4-dimethylaminopyridine (DMAP) method or a mixed anhydride method, in our search for potent anti-inflammatory compounds. The anti-inflammatory activity of these compounds was assessed by the carrageenan-induced paw edema assay in rats. The oximes (4, 5, and 13), O-lauroyloxime 1L, O-nicotinoyloximes (1N, 2N, 3N, and 4N), O-isonicotinoyloxime 1I, and O-2-pyridinecarbonyloxime 7P showed higher anti-inflammatory potency than aspirin, a prostaglandin cyclooxygenase inhibitor.     

Investigation of the reaction between sodium hydroxide and syn-and anti-isomers of 5-substituted 2-(4-chlorobutyryl)-aminobenzophenones oximes

By the reaction of syn-isomers of 5-substituted 2-(4-chlorobutyryl)aminobenzophenones oximes with NaOH syn-isomers of 5-substituted 2-(2-oxopyrrolidin-1-yl)benzophenones oximes were obtained. Similarly the anti-isomers of 5-substituted 2-(4-chlorobutyryl)aminobenzophenones oximes treated with NaOH underwent cyclization into anti-isomers of 5-substituted 2-(2-oxopyrrolidin-1-yl)benzophenones oximes. Crystal and molecular structures were investigated of the syn-isomer of 5-methyl-2-(2-oxopyrrolidin-1-yl)benzophenone oxime, the anti-isomer of 5-bromo-2-(2-oxopyrrolidin-1-yl)benzophenone oxime, and the syn-isomer of 5-methyl-2-(4-chlorobutyryl)aminobenzo-phenone oxime. The fragmentation features under the electron impact of syn-and anti-isomers of 5-substituted 2-(2-oxopyrrolidin-1-yl)benzophenones oximes are discussed.     

First Representatives of O-(2-Vinyloxyethyl)oximes

Previously unknown ketone and acetaldehyde O-(2-vinyloxyethyl)oximes were synthesized in 22-88% by reaction of the corresponding oximes with 2-chloroethyl vinyl ether in the system KOH-DMSO.     

Novel and efficient synthesis of N,N-dialkylaminoand O-alkylphenyl-2-(1-alkyl/phenyl-2-oxopropylidene) phosphonohydrazido oximes--potential marine fish toxin analogues. Part 2

A novel and efficient method for the synthesis of N,N-dialkylamino/O-alkyl phenyl-2-(1-alkyl/phenyl-2-oxopropylidene) phosphonohydrazido oximes 4 using activated silica has been developed. The reaction involves the condensation of substituted alpha-ketooxime and N,N-dialkylaminophenylphosphonohydrazides or O-alkylphenylphosphonohydrazides and gave the corresponding phosphonohydrazido oximes in excellent yields under mild conditions.     

Aza-Reformatsky-type reaction of alpha-iodomethyl ketone O-alkyl oximes promoted by titanium tetraiodide

Titanium tetraiodide promotes an aza-Reformatsky-type reaction of alpha-iodomethyl ketone O-alkyl oximes with carbonyl compounds to give beta-hydroxy ketone O-alkyl oximes in good to high yields.     

Iron powder and tin/tin chloride as new reducing agents of Meerwein arylation reaction with unexpected recycling to anilines

Abstract

Simple and rapid route for Meerwein arylation reaction using iron powder or a mixture of tin/tin chloride has been developed. In the presence of iron powder, different aryl diazonium salts reacted with methyl vinyl ketone, acrylates, and isopropenyl acetate. Production of oximes was detected as the main product with acrylates or in a mixture with β-aryl methyl ketones in the case of methyl vinyl ketone. The in situ produced HNO₂ from an excess of NaNO₂/HCl was trapped by alkyl aryl radical to form oximes in the E configuration form. The presence of tin/tin chloride mixture in the reaction of the aryl diazonium salts with methyl vinyl ketone produced Michael products along with β-aryl methyl ketones. The predicted α-aryl methyl ketones from the reaction of isopropenyl acetate with the diazotized anilines were obtained using iron or tin/tin chloride mixture.     

Ring transformation of 5-aroyl-3(2H)-isothiazolones to 1,2,5-oxathiazole and 1,2,3-thiadiazole derivatives

Reaction of 2-substituted-5-aroyl-3(2H)-isothiazolones 2 with hydroxylamine and phenylhydrazine was found to give (N-substituted-carboxamido)methylene derivatives of 1,2,5-oxathiazole and 1,2,3-thiadiazole, 5 and 7 , respectively. The formation of these heterocycles was ascribed to a mononuclear heterocyclic rear-rangement of the initially formed ketone derivatives, oximes and hydrazones, through a nucleophilic attack of the = N-OH and = N-NH- groups on the S N bond of the isothiazolone ring. In a similar manner, reaction of isothiazolones 2 with hydrazine was found to give 4-aryl-5-(N-substituted-carboxamido)methyl-1,2,3-thiadiazoles 17 .     

Selective synthesis of allylated oxime ethers and nitrones based on palladium-catalyzed allylic substitution of oximes

[reaction: see text] The viability of oximes as nucleophiles in transition-metal-catalyzed allylic substitution was examined. The oxygen atom of oxime acted as a reactive nucleophile in the reaction of a pi-allyl palladium complex. In the presence of Pd(PPh3)4, the allylic substitution of oximes with allylic carbonate afforded the linear O-allylated oxime ethers selectively without a base. In contrast, the palladium-catalyzed reaction with allylic acetate proceeded smoothly in the presence of K2CO3 or Et2Zn as a base. Selective formation of nitrones was achieved by using palladium(II) catalyst. In the presence of Pd(cod)Cl2, the allylic substitution of oximes with allylic acetate afforded the N-allylated nitrones under solvent-free conditions, as a result of the reaction with the nitrogen atom of oximes.     

Efficient and divergent synthesis of fully substituted 1H-pyrazoles and isoxazoles from cyclopropyl oximes

Efficient and divergent one-pot synthesis of fully substituted 1H-pyrazoles and isoxazoles from cyclopropyl oximes based on reaction conditions selection is reported. Under Vilsmeier conditions (POCl3/DMF), substituted 1 H-pyrazoles were synthesized from 1-carbamoyl, 1-oximyl cyclopropanes via sequential ring-opening, chlorovinylation, and intramolecular aza-cyclization. In the presence of POCl3/CH2Cl2, substituted isoxazoles were obtained from the cyclopropyl oximes via ring-opening and intramolecular nucleophilic vinylic substitution (SNV) reactions.