cis-4-甲氧基环己基-1-氨基甲酸的合成和优化

[目的]研究cis-4-甲氧基环己基-1-氨基甲酸的合成新方法。[方法]以cis-8-甲氧基-1,3-二氮杂螺[4,5]癸-2,4-二酮(简称LC-酰胺)为起始原料,在氢氧化钡碱性条件下水解得到目标产物。[结果] cis-4-甲氧基环己基-1-氨基甲酸的顺式含量达98%以上,收率达96%。[结论]该合成新方法具有含量高、收率高、操作简便,能有效避免副产氯化钠盐的生成。     

五氟磺草胺中间体2-氨基-5,8-二甲氧基[1,2,4]三唑[1,5-c]嘧啶的合成研究

以甲氧基乙酸甲酯、甲酸乙酯和尿素为原料,经缩合、环化、三氯氧磷氯化、氨水取代得到2-氯-4-氨基-5-甲氧基嘧啶,然后与N-乙氧基羰基异硫氰酸酯反应、盐酸羟胺环化、甲氧基化得到目标产物2-氨基-5,8-二甲氧基[1,2,4]三唑[1,5-c]嘧啶。总收率27.2%。     

甲硫基嘧啶-5-羧酸乙酯衍生物的绿色氧化

(S)-4-(3-氯-4-甲氧基苄氨基)-2-(2-羟甲基-1-吡咯烷基)-5-嘧啶甲酸乙酯(3)是合成阿伐那非的关键中间体之一。以钨酸钠为催化剂,H2O2氧化4-(3-氯-4-甲氧基苄氨基)-2-甲硫基-5-嘧啶甲酸乙酯(1),得亚砜(2a)与砜(2b)的混合物,再与L-脯氨醇反应得到(S)-4-(3-氯-4-甲氧基苄氨基)-2-(2-羟甲基-1-吡咯烷基)-5-嘧啶甲酸乙酯(3);研究了氧化剂用量、催化剂用量、溶剂、反应温度等因素对反应的影响,利用响应面设计实验方案进行优化,得出最佳工艺条件,验证实验与优化结果相符。产物结构经~1H-NMR、~(13)C-NMR、ESI-MS、FT-IR等表征及分析予以确认。     

5,6-二甲氧基-1-茚酮与1-苄基-4-氯甲基哌啶的合成

以3,4-二甲氧基苯甲醛为原料,经过缩合、还原、环合得到5,6-二甲氧基-1-茚酮,总收率为74.7%。以4-哌啶甲酸乙酯为原料,经苄基化、还原、氯化,得到1-苄基-4-氯甲基哌啶,总收率52.5%。经1H NMR、FTIR、MS分析确认为目标产物。     

2-己基-4-乙酰氧基四氢呋喃顺反异构体的制备

以烯丙基氯和庚醛为原料通过格氏反应制得1-癸烯-4-醇,产率86%;1-癸烯-4-醇用间氯过氧苯甲酸氧化,得到1,2-环氧-4-癸醇,产率89%;然后,在碳酸钾的作用下1,2-环氧-4-癸醇进行分子内的亲核取代反应,关环得到2-己基-4-羟基四氢呋喃顺反异构体的混合物,产率90%,trans-和cis-异构体比例为53∶47;2-己基-4-羟基四氢呋喃与对硝基苯甲酰氯反应,酯化产物通过柱层析分离,得到trans-和cis-2-己基-4-四氢呋喃对硝基苯甲酸酯,产率分别为52%和40%;分离后的酯化产物的顺反异构体在碱性条件下水解,得到trans-和cis-2-己基-4-羟基四氢呋喃,产率分别为85%和82%;trans-和cis-2-己基-4-羟基四氢呋喃与乙酸酐反应,得到trans-和cis-2-己基-4-乙酰氧基四氢呋喃,产率分别为83%和85%。trans-和cis-2-己基-4-乙酰氧基四氢呋喃经过GC-O进行了评香分析和稀释因子的测定,结果表明,两者具有不同的香气特征和香气强度。     

C.I.分散蓝257及其中间体的合成

研究了以间乙酰氨基苯胺和对甲苯磺酸-β-甲氧基乙酯为原料,在缚酸剂氧化镁的作用下合成间乙酰氨基-N,N-二(β-甲氧基乙基)苯胺的工艺路线,然后与2-氰基-4-硝基-6-溴苯胺的重氮盐偶合反应合成C.I.分散蓝257,总收率80%,并对产品进行上染性能测试.合成中间体间乙酰氨基-N,N-二(β-甲氧基乙基)苯胺较佳工艺条件为:水与对甲苯磺酸-β-甲氧基乙酯及间乙酰氨基苯胺摩尔比为10∶ 2.2∶ 1,且采用分段升温.     

L-甲基多巴的合成工艺改进

以3,4-二甲氧基苯丙酮为原料,经Strecker 反应得到(3',4'-二甲氧基苯基)-2-氨基-2-甲基丙腈,然后用L-酒石酸拆分得到L-(3',4'-二甲氧基苯基)-2-氨基-2-甲基丙腈盐酸盐,再经水解、脱甲基得到目标产物L-甲基多巴,收率为50.4%.     

6-硝基-4-二甲氨基甲基-5-羟基-1-甲基-2-苯硫甲基-1H-吲哚-3-羧酸乙酯的合成

以对苯醌和3-(甲基氨基)-2-丁烯酸乙酯为起始原料,经Nenitzescu反应、乙酰化、硝化、溴代、缩合、Mannich反应得到一个新化合物6-硝基-4-二甲氨基甲基-5-羟基-1-甲基-2-苯硫甲基-1H-吲哚-3-羧酸乙酯,总产率19.3％.反应中间产物和目标产物结构采用1 HNMR和质谱确认.     

2-（3-氯-2-吡啶基）-5-氧代-3-吡唑烷甲酸乙酯的合成

以3-氨基吡啶为原料,经取代、重氮化得到2,3-二氯吡啶,再与水合肼经亲电取代制得3-氯-2-肼基吡啶。所得产品无需提纯可直接用于下一步反应。所得产物与马来酸二乙酯在氮气保护条件下,以无水乙醇为溶剂,反应得到有机中间体2-(3-氯-2-吡啶基)-5-氧代-3-吡唑烷甲酸乙酯,反应总产率为48.0%。所得产物经IR、1HNMR确定其结构。并对合成工艺进行优化,所得适宜工艺条件(以3-氯-2-肼基吡啶228.57 mmol计):在无水无氧反应体系中,回流状态下滴加马来酸二乙酯速度为10 s/滴时,回流反应1 h,产率为80.1%。     

6,7-二甲氧基异喹啉-1-甲酸乙酯的高效合成

以高藜芦胺为原料,先与草酸二乙酯酰胺化,再经一锅法反应关环、氧化制得6,7-二甲氧基-异喹啉-1-甲酸乙酯,并对反应条件进行优化筛选,反应条件优化后总收率达86.4%。产物及中间体结构经1H NMR、13C NMR鉴定。操作简单、反应条件温和,具有工业应用前景。     

Versuche zur Herstellung linolsäurearmen Ölsäureesters über eine Hydrierung mit Palladium

The Preparation of Oleic Ester with Reduced Linoleic Acid Content by Hydrogenation with Palladium By hydrogenation with palladium on charcoal low contents of linoleic acid can be reduced quite selectively in the presence of an excess of oleic acid ester. In a mixture of fatty acid methylesters the content of linoleic acid was reduced from 10% to 2% with the formation of 3% cis-, 4% transmonoenes and 1% saturated acid.     

Preparation of deuterium-labelled methyl linoleate and its geometric isomers from natural seed oils

Multi-gram quantities of deuterium-labelled methyl linoleate (methyl cis-9,cis-12-octadecadienoate) and its geometric isomers are readily synthesized fromCrépis alpina (70–80% cis-9-octadecen-12-ynoic acid) andVernonia galamensis (70–80% 12,13-epoxy-cis-9-octadecenoic acid) seed oils. Methylcis- 9,cis- 12- andtrans- 9,cis- – octadecadienoate-12,13-d₂ were prepared by the Lindlar-catalyzed reduction (with D₂ gas) of methylcis- 9- and trans-9-octadecen-12-ynoates, respectively. Methyltrans- 9- octadecen-12-ynoate was synthesized by thep-toluene-sulfinic acid-catalyzed isomerization of the corresponding cis isomer. Methylcis- 9fiis- 12., trans- 9fiis- 12;cis- 9,trans- 12- andtrans- 9, frans-12-octadecadienoate-d₂, d₄ and d₆ were prepared by the Wittig coupling (with stereochemical control) of the appropriate d₂-, d₄- or de-alkyltriphenyl-phosphonium salt with methyl 12-oxo-cis-9- ortrans- 9- dodecenoate (prepared by the para-periodic acid cleavage of methyl 12,13-dihydroxy-cis-9- or trans-9-octadecenoate). Thecis dihydroxy ester was synthesized fromVernonia galamensis seed oil by acetolysis, saponification and then esterification. Thecis dihydroxy ester was isomerized by nitric acid/sodium nitrite to thetrans form and purified by silver resin chromatography. Isotopic purities ranged from 88% (for the d₆ isomers) to 99% (for the d₂ isomers). The mention of firm names or trade products does not imply that they are endorsed or recommended over other firms or similar products not mentioned.     

A study of the structures and reactions of some methyl substituted unsaturated C18 ester intermediates in the synthesis of a racemic mixture of 10-methyloctadecanoic acid

Methyl 10-undecenoate was hydrated to methyl 10-hydroxyundecanoate using mercury (II) acetate in aqueous tetrahydrofuran (THF). Chromic acid oxidation of methyl 10-hydroxyundecanoate gave methyl 10-oxoundecanoate, which was hydrolyzed to 10-oxoundecanoic acid. Reaction of n-octyl magnesium bromide complex in THF with 10-oxoundecanoic acid furnished 10-hydroxy-10-methyloctadecanoic acid after hydrolysis. The latter compound was esterified, and dehydration of methyl 10-hydroxy-10-methyloctadecanoate withp-toluenesulfonic acid in benzene gave a mixture of unsaturated branched fatty ester intermediates:viz. methyl 10-methyl-9-octadecenoate, 10-methyl-10-octadecenoate and 10-octyl-10-undecenoate. Treatment of the mixture of unsaturated branched fatty ester intermediates with mercury (II) acetate in methanol gave exclusively methyl 10-methoxy-10-methyloctadecanoate. Epoxidation of the same mixture of unsaturated fatty esters withm-chloroperbenzoic acid provided a mixture of epoxy derivatives: methyl 9,10-epoxy-10-methyloctadecanoate, 10,11-epoxy-10-methyloctadecanoate and 2-octyl-oxirane-nonanoate. Catalytic hydrogenation of the mixture of unsaturated fatty esters gave a racemic mixture of methyl 10-methyloctadecanoate, which was hydrolyzed to 10-methyloctadecanoic acid. The structures of the mixture of unsaturated branched fatty ester intermediates and their derivatives were characterized by chemical and spectroscopic analyses.     

Soy lecithin-monoester interchange reaction by microbial lipase

Modification of the fatty acid composition of soy lecithin, principally at its 1-position, was investigated by interchange reaction with the methyl ester of individual fatty acids and a lipase as the catalyst. The consequent effect on the surface activity of soy lecithin was also examined. The interchange reaction was carried out by heating a mixture of soy lecithin and methyl ester of a fatty acid at 60°C for 48 h with 10% (by weight of the reactants) Mucor miehei lipase. The lipase was filtered from the reaction mixture, and the product was isolated by combination of acetone extraction, which removed the methyl ester fraction, and by preparative thin-layer chromatography separation. The soy lecithin showed distinct change in its fatty acid composition in the sn-1 position. Capric acid was incorporated by 8.4%, while lauric acid and myristic acid were introduced at 14.1 and 15.7%, respectively. The linolenic acid percentage was increased by about 10 units. The interfacial tension of soy lecithin changed significantly after incorporation of various saturated fatty acids.     

Thermal Decomposition of Some Acetoxyoctadecenoates and Acetoxyoctadecadienoates

The rates of the thermal decomposition (dehydroacetoxylation) and the activation energies of the following three samples have been determined: A) acetylated methyl ricinoleate; B) methyl ester mixture of vicinally unsaturated acetoxyoctadecenoates prepared by reacting methyl oleate and mercuric acetate in acetic acid; C) methyl ester mixture of vicinally unsaturated acetoxyoctadecadienoates prepared by reacting methyl linoleate and mercuric acetate in acetic acid. The thermal decomposition is shown to be a first-order reaction.     

聚乙二醇单甲醚脂肪酸酯的碱催化合成及性能

在碱催化下通过聚乙二醇单甲醚（ＰＧＭＥ）和脂肪酸甲酯的酯交换反应合成了ＰＧＭＥ脂肪 酸酯。在酯和醇醚摩尔比为１：１．２．催化剂质量分数为０５％、反应温度１２０℃、反应时间６．５ｈ条 件下,对脂肪酸甲酯的摩尔收率可达９０％。用ＩＲ、~（１３）ＣＮＭＲ对产物结构进行了确证,同时对产物 的表面物性进行了测试。     

2-甲基-4-甲醛肟基苯甲酸甲酯的合成

以2-甲基-4-溴苯甲酸为起始原料,经酰化和酯化反应制得2-甲基-4-溴苯甲酸甲酯,2-甲基-4-溴苯甲酸甲酯与氰化亚铜在DMF中发生取代反应得到2-甲基-4-氰基苯甲酸甲酯,接着与盐酸羟胺在碳酸钠存在下反应得到标题化合物,总收率为61%,纯度为99.2%。化合物的结构经IR、MS、~1HNMR和~(13)CNMR等确证。该路线中目标产物肟经由氰基直接一步反应制得,工艺简单可靠、产品收率高。该方法为肟的合成提供了良好的实验基础。     

Isolation of methylcis,cis-5, 13-docosadienoate fromLimnanthes douglasii oil

Methylcis,cis-5,13-docosadienoate has been isolated from the mixed methyl esters of the fatty acid moiety ofLimnanthes douglasii oil by a combination of low temperature fractional crystallization and fractionation of mercuric acetate adducts. The methyl ester and its free acid have been characterized. So. Util. Res. Dev. Div., ARS, USDA.     

Hydroperoxide formation during autoxidation of conjugated linoleic acid methyl ester

The aim of this study was to investigate whether hydroperoxides are formed in the autoxidation of conjugated linoleic acid (CLA) methyl ester both in the presence and absence of α‐tocopherol. The existence of hydroperoxide protons was confirmed by D₂O exchange and by chemoselective reduction of the hydroperoxide groups into hydroxyl groups using NaBH₄. These experiments were followed by nuclear magnetic resonance (NMR) spectroscopy. The ¹³C and ¹HNMR spectra of a mixture of 9‐hydroper‐oxy‐10‐trans,12‐cis‐octadecadienoic acid methyl ester (9‐OOH) and 13‐hydroperoxy‐9‐cis, 11‐trans‐octadecadienoic acid methyl ester (13‐OOH), which are formed during the autoxidation of methyl linoleate, were studied in detail to allow the comparison between the two linoleate hydroperoxides and the CLA methyl ester hydroperoxides. The ¹³CNMR spectra of samples enriched with one of the two linoleate hydroperoxide isomers were assigned using 2D NMR techniques, namely Correlated Spectroscopy (COSY), gradient Heteronuclear Multiple Bond Correlation (gHMBC), and gradient Heteronuclear Single Quantum Correlation (gHSQC). The ¹³C and ¹H NMR experiments performed in this study show that hydroperoxides are formed during the autoxidation of CLA methyl ester both in the presence and absence of α‐tocopherol and that the major isomers of CLA methyl ester hydroperoxides have a conjugated monohydroperoxydiene structure similar to that in linoleate hydroperoxides.     

生物柴油低温流动改进剂复配研究

采用碱催化法制备菜籽油生物柴油和棕榈油生物柴油,对其主要品质指标进行分析;考察了添加不同的柴油低温流动改进剂及其复配物对生物柴油低温流动性能的影响。结果表明,柴油低温流动改进剂能够改善生物柴油低温流动性能;将其进行复配后,能表现出协同效应,取得更好的降滤效果,尤其能使饱和脂肪酸甲酯含量高的棕榈油生物柴油冷滤点降低8℃;不同生物柴油对柴油低温流动改进剂或其复配物感受性存在较大差异,不饱和脂肪酸甲酯含量高,且脂肪酸甲酯种类较多、分布较广的菜籽油生物柴油对单一低温流动改进剂感受性好,而饱和脂肪酸甲酯含量高,且脂肪酸甲酯种类分布较集中的棕榈油生物柴油对复配物感受性好。