1-甲基-3-正丙基-4-氨基-5-吡唑羧酰胺的制备

1 甲基 3 正丙基 5 吡唑羧酸经硝酸 -浓硫酸硝化制得 1 甲基 3 正丙基 4 硝基 5 吡唑羧酸 ,收率 85 %;用氯化亚砜将其酰氯化制得 1 甲基 3 正丙基 4 硝基 5 吡唑羧酰氯 ,该吡唑羧酰氯与浓氨水反应制得 1 甲基 3 正丙基 4 硝基 5 吡唑羧酰胺 ,收率 90 %;硝基吡唑羧酰胺在乙醇中用氯化亚锡还原制得 1 甲基 3 正丙基 4 氨基 5 吡唑羧酰胺 ,收率 84%。研究了反应的较佳合成工艺条件 ,产品经TLC、IR及MS谱进行了结构表征。     

2-氯-5-(4-氯-1-甲基-5-三氟甲基-1H-吡唑-3-基)-4-氟苯甲醛的合成

2－氯－5－（4－氯－1－甲基－5－三氟甲基－1H－吡唑－3－基）－4－氟苯甲醛是合成除草剂的中间体，它可以通过以下2步反应制得：首先，4－氯－3－（4－氯－2－氟－5－甲基苯基）－1－甲基－5－三氟甲基－1H－吡唑在乙酸／乙酐混合溶剂中用三氧化铬氧化，然后，在乙醇／水混合溶剂中，用碳酸氢钠催化水解得目的的产物，2步反应总收率达到71．6％。     

4-氨基-1-甲基-3-正丙基吡唑-5-酰胺的合成

从1-甲基-3-正丙基吡唑-5-羧酸(A)出发,用改进的工艺,经过硝化、酰胺化及还原合成了4-氨基-1-甲基-3-正丙基吡唑-5-酰胺(D)。     

4-氨基-1-甲基-3-正丙基吡唑-5-甲酰胺合成工艺研究

以 3 正丙基吡唑 5 羧酸乙酯为起始原料 ,经多步反应合成了 4 氨基 1 甲基 3 正丙基吡唑 5 甲酰胺 ,并对工艺进行了如下改进 :(1)将甲基化、水解两步反应合并为“一勺烩”工艺 ,中间产物不需硅胶柱分离、提纯 ,直接进行水解 ;(2 )硝化后处理增加了溶媒提取工序 ;(3)还原反应采用催化还原法 ,以价廉的甲酸铵代替氯化亚硒作还原剂。总收率达到 39 3% ,较原工艺提高了8 5 % ,具有操作简单 ,反应条件温和 ,宜于工业化生产 ,为合成 4 氨基 1 甲基 3 正丙基吡唑 5 甲酰胺提供了一个较好的方法。     

3—正丙基—5—羟基—1—甲基比唑的合成研究

以2－戊酮和草酸二乙酯为起始原料，经Claisen缩合，环化，甲基化和皂化等反应制得目标化合物3－正丙基－5－羟基－1－甲基吡唑3。文献报道的合成方法为四步法，在此基础上加以改进，形成了两种新的合成路线，即三步法和两步法，其收率均高于四步法，高出27．0％。     

1-甲基-3-丙基-4-硝基吡唑-5-羧酸的合成研究

以1-甲基-3-丙基吡唑-5-甲酸为原料,采用二氯甲烷为溶剂,合成了1-甲基-3-丙基-4-硝基吡唑-5-羧酸。试验研究了影响反应收率的多种因素,确定了最佳工艺条件:搅拌转速600 r/min;反应温度70°C;反应时间5~6 h;硫酸的浓度为90%。     

1-甲基-3-正丙基吡唑-5-甲酸的合成

以2-戊酮和草酸二乙酯为原料,经缩合、环合、甲基化、水解等四步反应合成了西地那非的关键中间体-1-甲基-3-正丙基吡唑-5-甲酸。考察了环合反应的影响因素,探讨并找到了较佳的反应条件：反应时间2h;反应温度60-65℃;2,4-二氧代庚酸乙酯与水合肼摩尔比1：1．2,总收率达72％。     

2-[3-(二乙基氨基)丙基]-5-乙基吡啶的合成

由2－甲基－5－乙基吡啶在金属钠作用下，与（（C2H5）2N（CH2）2Cl作用，发生的侧镀金属化及烃基化反应，合成了2－[3－（二乙基氨基）丙基]－5－乙基吡啶，其结构经元素分析、MS、1HNMR、IR、UV分析确证。     

5-正己基-2-巯基-1,3,4-噁二唑合成研究

以庚酸乙酯为原料，先与水合肼反应生成庚酰肼，庚酰肼在氢氧化钾存在下与二硫化碳经环合、酸化、提纯得到5－正已基-2－巯基－1，3，4－恶二唑。最适宜的工艺条件为n(庚酸乙酸）:n(水合肼）＝1：1．8,n（庚酰肼）：n（二硫化碳）：n(氢氧化钾）＝1：1．6：1．1，同时控制二硫化碳加料时间40min，并采用石油醚作洗涤剂，总收率达到60％。     

两种医药中间体的合成研究

(一)1-甲基-3-正丙基-5-吡唑羧酸的合成研究。烷基吡唑衍生物是具有广泛用途的化合物。它们中有些具有杀菌，杀酶作用，有些能防止植物病虫害，有些还有除草性能。在医药方面烷基吡唑衍生物具有治疗心血管疾病和神经系统疾病的功能，是精细化工领域中的一类重要的中间体。1-甲基-3-正丙基-5-吡唑羧酸是合成一种治疗心血管疾病药物的中间体，资料报道它是由草酸二乙酯和2-戊酮经claisen酯缩合反应、用水合肼环化、甲基化反应、水解反应四步完成，总收率61．4％。在西安近代化学研究所的苏天铎等的研究中，用甲基肼代替水合肼将环化与甲基化一步完成，省去了甲基化反应，三步合成出目标化合物，     

N1-(2-苯基-1,2,3-三唑-4-甲酰基)-吡唑类衍生物的合成

利用２－苯基－１,２,３－三唑－４－甲酰肼（１）分别与３－芳基偶氮乙酰丙酮（２）和３－芳基偶氮乙酰乙酸乙酯（３）在酸性条件下环化,制得１２个新的Ｎ１－（２－苯基－１,２,３－三唑－４－甲酰基（－３,５－二甲基－４－芳基偶氮吡唑（４）和Ｎ１－（２－苯革－１,２,３－三唑－４－甲酰基）－３－甲基－４－芳基偶氮－２－吡唑啉－５－酮（５）,用元素分析、ＩＲ、＾１ＨＮＭＲ和ＭＳ确定了它们的结构。     

Dehydration of 2-(2-Arylethyl)-2-hydroxy-4-oxopentanoic Acids and their hydrazones to form heterocycles

Dehydration of 2-(2-arylethyl)-2-hydroxy-4-oxopentanoic acids 1 with hydrochloric acid/acetic acid, affords 3-(2-arylethyl)-5-hydroxy-5-methyl-2(5H)-furanones 4 . Compounds of type 1 and 4 represent suitable precursors for the formation of pyridazin-3-ones 7 as they smoothly react with hydrazine. A new series of s-triazolo[4,3-b]pyridazin-3-ones 12 and tetrazolo[1,5-b]pyridazines 15 are obtained from the 3-chloropyridazines 11 upon treatment with semicarbazide and sodium azide, respectively. Reaction of 11 with phenyl- acetyl-hydrazine provides 3-benzyl-6-phenyl-8-(2-phenyl-ethyl)-s-triazolo[4,3-b]pyridazine 13 via dehydrative cyclization of the intermediate 14 which was clarified to exhibit tautomeric equilibria between enol–hydrazine form A and keto–hydrazine form B by means of ¹H and ¹³C NMR spectroscopy. Attempts to synthesize 3-alloxy-pyridazines 18 by reacting 11 with sodium alloxide afford N-allyl compounds 17 .     

Synthesis and Antimicrobial Evaluation of Some Novel Bis-α,β-Unsaturated Ketones,Nicotinonitrile, 1,2-Dihydropyridine-3-carbonitrile,Fused Thieno[2,3-b]pyridine and Pyrazolo[3,4-b]pyridine Derivatives

The title compounds were prepared by reaction of 1,1′-(5-methyl-1-phenyl-1H-pyrazole-3,4-diyl)diethanone (1) with different aromatic aldehydes 2a–c, namely Furfural (2a), 4-chlorobenzaldehyde (2b) and 4-methoxybenzaldhyde (2c) to yield the corresponding α,β-unsaturated ketones 3a–c. Compound 3 was reacted with malononitrile, 2-cyanoacetamide or 2-cyanothioacetamide yielded the corresponding bis[2-amino-6-(aryl)nicotinonitrile] 4a–c, bis[6-(2-aryl)-2-oxo-1,2-dihydropyridine-3-carbonitrile] 5a–c or bis[6-(2-aryl)-2-thioxo-1,2-dihydropyridine-3-carbonitrile] 6a,b, respectively. The reaction of compound 6a with each of 2-chloro-N-(4-bromophenyl) acetamide (7a), chloroacetamide (7b) in ethanolic sodium ethoxide solution at room temperature to give the corresponding 4,4′-(5-methyl-1-phenyl-1H-pyrazole-3,4-diyl)bis-6-(2-furyl)thieno[2,3-b]pyridine-2-carboxamide] derivatives 9a,b. While compound 6a reacted with hydrazine hydrate yielded the 4,4′-(5-methyl-1-phenyl-1H-pyrazole-3,4-diyl)bis[6-(2-furyl)-1H-pyrazolo[3,4-b]pyridin-3-amine] 11. The structures of the products were elucidated based on their spectral properties, elemental analyses and, wherever possible, by alternate synthesis. Antimicrobial evaluation of the products was carried out.     

Synthesis of disazo dyes derived from heterocyclic components

In this study, 2-phenylhydrazone-3-ketiminobutyronitrile was synthesised and reacted with hydrazine hydrate and phenylhydrazine to afford the corresponding 5-amino-3-methyl-4-phenylazo-1H-pyrazole and 5-amino-3-methyl-4-phenylazo-1-phenylpyrazole, respectively. Ten novel disazo dyes were then synthesised by diazotisation of 5-amino-3-methyl-4-phenylazo-1H-pyrazole and 5-amino-3-methyl-4-phenylazo-1-phenylpyrazole using nitrosylsulphuric acid, and coupling with 4-hydroxy-6-methyl-2-pyrone, 4-hydroxycoumarin, 3-methyl-1H-pyrazolin-5-one, 3-methyl-1-phenylpyrazolin-5-one and 3-cyano-6-hydroxy-4-methyl-2-pyridone. The dyes were characterised by elemental analysis and spectral methods. The solvatochromic behaviour of these disazo dyes in various solvents was evaluated. Received: 18 May 2005; Accepted: 8 July 2005.     

1-(5-(4-氯苯基)-1-(2,4-二氯苯基)-4-甲基-1H-吡唑-3-基)-3-(吡啶-3-基甲基)脲的合成

以5-(4-氯苯基)-1-(2,4-二氯苯基)-4-甲基-1H-吡唑-3-甲酸与二氯亚砜为起始原料,经酰氯化反应、酰胺反应、霍夫曼重排以及水解反应生成中间体5-(4-氯苯基)-1-(2,4-二氯苯基)-3-氨基-4-甲基-1H-吡唑,再经过与氯甲酸苯酯反应、胺酯交换反应得到标题化合物,其结构经1HNMR、MS谱确证,总收率26.9%。     

邻杂环(噁二唑)甲酰苯胺类化合物的设计合成及杀虫活性初步研究

以超高效杀虫剂氯虫苯甲酰胺为先导,在酰胺部分引入了邻杂环(噁二唑),设计并合成了16个含邻杂环(噁二唑)甲酰苯胺类新化合物。生测结果表明,化合物普遍具有高杀虫活性,在10 mg/L剂量下对小菜蛾的致死率均大于80%。本研究结果为该类化合物的创制提供了参考。     

Studies on the Vilsmeier-haack reaction. Part XIII: Novel heterocyclo-substituted 4,4′-bi-pyrazolyl dithiocarbamate derivatives

5-Imino-3-methyl-l-phenyl-2-pyrazoline-4-dithiocarbamic acid (I) underwent simultaneous formylation and dimerization reactions with the Vilsmeier reagent giving 4-[5′-imino-3-(1″-formyl-2″-dimethylaminoethenyl)-3′-methyl-1′-phenyl-1′H-pyrazolo-4′-dithiocarbamyl-2,4-dihydro-3-imino-5-methyl-2-phenyl-1-pyrazoline]dithiocarbamate (II) which hydrolysed with sodium hydroxide to give 4-[3′-(1″-formyl-2″-hydroxyethenyl)-3′-methyl-1-phenyl-1′-H-pyrazolo-4′-dithiocarbamyl-1′-pyrazoline]dithiocarbamate-5,5′-dione (IV). Treatment of II and/or IV with morpholine, piperidine, piperazine, hydroxylamine, hydrazine hydrate or phenylhydrazine afforded the corresponding dipyrazolo-4,4′-dithiocarbamate derivatives with different heterocyclic systems at the 3-position. The structures of these compounds were confirmed by microanalysis data, IR and ¹H-NMR spectrometry. All synthesized compounds have been screened in vitro against Gram-positive and Gram-negative bacteria, and fungi.     

Synthesis of some new 3-(2′-heterocyclicethyl)-2-methyl-3,4-dihydroquinazolin-4-one derivatives as antimicrobial agents

3-(2′-Chloroethyl)-2-methyl-3,4-dihydroquinazolin-4-one was reacted with acetylacetone, ethyl acetoacetate and diethylmalonate in the presence of sodium ethoxide to afford the alkylation products IV, V and VI , Compounds IV, V and VI were reacted with hydrazine hydrate, phenylhydrazine, hydroxylamine hydrochloride, urea and thiourea to yield 3-(2′-heterocyclicethyl)-2-methyl-3,4-dihydroquinazolin-4-one derivatives VII-XV . The structures of the synthesized compounds were elucidated by elemental analyses and spectroscopic (IR and XH-NMR) analyses. The prepared compounds were tested for their antimicrobial activities in comparison with tetracycline as a reference compound.     

The STOBBE condensation. XI. The cyclisation of (Z)- and (E)-3-methoxycarbonyl-2-methyl-4-(2′-naphthyl)-4-phenyl-but-3-enoic acids to the corresponding polysubstituted phenanthrene and naphthalene derivatives

(Z)- and (E)-3-methoxycarbonyl-2-methyl-4-(2′-naphthyl)-4-phenyl-but-3-enoic acids 1 a and 4 a have been converted into methyl-4-acetoxy-3-methyl-1-phenylphenanthrene-2-carboxylate 2 a and methyl 4-acetoxy-3-methyl-1-(2′-naphthyl)-2-naphthoate 5 a . The derived phenolic acids 2 b and 5 b are converted to methyl 4-methoxy-3-methyl-1-phenyl-phenanthrene-2-carboxylate 2 c and methyl 4-methoxy-3-methyl-1-(2′-naphthyl)-2-naphthoate 5 c ; which are saponified to the corresponding methoxy acids 2 d and 5 d . Alcoholysis of the anhydrides 3 and 6 gives the corresponding half-esters 1 c and 4 c , respectively.