Zur Konstitution der Reaktionsprodukte aus Phenacylthioglykolsäure und Benzylmercaptan sowie aus Phenacylbenzylsulfid und Thioglykolsäure

On the Structure of the Reaction Products from Phenacyl Thioglycolic Acid and Benzyl Mercaptan and from Phenacyl Benzyl Sulfide and Thioglycolic Acid Phenacyl benzyl sulfide gives with thioglycolic acid the expected mercaptol C₆H₅C(SCH₂COOH)₂CH₂SCH₂C₆H₅ ( 5 ) as the only reaction product, while phenacyl thioglycolic acid and benzyl mercaptan give the mercaptol C₆H₅C(SCH₂C₆H₅)₂CH₂SCH₂COOH ( 6 ) as well as the mercaptal C₆H₅CH(SCH₂C₆H₅)Ch(SCH₂C₆H₅)₂ ( 4 ). The reactions took place in presence of hydrochloric acid. On the basis of the synthetic and the n.m.r. spectroscopic studies the reaction mechanisms are discussed.     

硫氢化钠法常压合成巯基乙酸

研究了以硫氢化钠和氯乙酸钠为原料常压合成巯基乙酸。适宜工艺条件为 :硫氢化钠溶液 pH值在 9左右 ,浓度为 0 65～ 0 70mol·L- 1,相应的氯乙酸钠溶液浓度为 2 0～ 1 5mol·L- 1,氯乙酸钠和硫氢化钠配比为 1∶1 3(mol) ,反应温度为 5 5± 1℃ ,反应时间为 12min ,巯基乙酸的收率为 82 %～ 87%。     

Radikalische Cyclisierung von Petroselinsäure

Free-Radical Cyclization of Petroselinic Acid Petroselinic acid was cyclized via methyl 2-iodopetroselinate ( 13 ) with tributyltin hydride to give methyl trans- and cis-2-dodecyl-1-cyclopentanecarboxylate ( 14 ). The atom-transfer method with hexabutylditin resulted in the formation of bicyclic γ-lactones 16 and methyl trans-2-(1′-iodododecyl)-1-cyclopentanecarboxylate (trans- 17 ). The same products were obtained with the new initiator system SnCl₂/AgOAc. This method showed, if compared with the other methods, the shortest reaction time, the highest yield and stereoselectivity combined with a very simple work-up procedure and the use of less toxic chemicals.     

二硫化钠法合成巯基乙酸的研究

概述了巯基乙酸的用途、合成方法 ,研究了二硫化钠法合成巯基乙酸的主要影响因素。实验从硫化钠、硫磺等基本原料出发 ,首先制得二硫化钠溶液 ,然后将二硫化钠同氯乙酸钠反应合成二硫代甘醇酸 ,最后用硫化钠溶液还原得到巯基乙酸。试验探讨了反应物料配比、反应温度、pH值、反应时间等因素对反应转化率的影响 ,实验结果表明该法的转化率可达 96 %左右 ,其具体反应条件如下 :硫化钠∶硫∶氯乙酸钠 (mol) =1.2∶1.4 4∶1.0 0 ,pH值 =7.5,合成二硫代甘醇酸的温度为 35℃ ,时间为 30min     

Nucleophile Substitutionen an Bischlornitrosoverbindungen. III. Reaktionen mit Salzen und Estern der Dithiocarbazinsäure sowie der N-Phenyldithiocarbazinsäure

Nucleophilic Substitutions with Bischloronitroso Compounds. III. Reactions with Salts and Esters of the Dithiocarbazinic Acid and the N-Phenyldithiocarbazinic Acid Bischloronitroso compounds 1 react with salts of the dithiocarbazinic acid to give S-(β-oximinoalkyl)-esters of the dithiocarbazinic acid. The esters easily cyclise to the corresponding 1,3,4-thiadiazine-2-thiones. Esters of the dithiocarbazinic acid lead to 2-alkylthio-1,3,4-thiadiazines. The structure of possible tautomeres follows from i.r.-, u.v./vis- and n.m.r.-spectra.     

Zur Bildung von Ölsäureepoxid bei der Lagerung technischer Ölsäure

Formation of Oleic Acid Epoxide at the Storage of Oleic Acid of Technical Quality Oleic acid epoxid 1 is produced by reaction with 9S-hydroperoxy-10-cis-12-trans-otadecadienoic acid 2 (9S-linoleic acid hydroperoxid, 9S-LOOH) slowly at room temperature. 9S-LOOH is obtained in a slow reaction, if linoleic acid is kept at room temperature in the air. Thus oleic acid of technical quality which contains always 10–30% of linoleic acid is transformed slowly even at room temperature (via oxidation of linoleic acid to its hydroperoxide) into oleic acid epoxide.     

Chemoenzymatische Synthese von 13C-markierter S-(-)-Äpfelsäure

Chemoenzymatic Synthesis of ¹³C-Labeled S-(-)-Malic Acid The first regio- and stereospecific synthesis of S-(-)-¹³C-malic acid 5 with a high incorporation of ¹³C and excellent enantiomeric excess is described. S-(-)-¹³C-malic acid 5 was synthesized in a three-step reaction starting with ethyl acetate 2 and diethyl oxalate 1 . The produced sodium diethyl oxaloacetate 3 was then enantioselectively reduced with bakers' yeast to S-(-)-¹³C-malic acid diethylester 4 which was hydrolyzed to S-(-)-¹³C-malic acid 5 .     

Über heteroorganische Verbindungen. IL. Zur Umsetzung von N-Morpholinoschwefelchlorid mit O-Alkyl-äthanthiophosphoniger Säure und O-Äthyl-äthan-dithiophosphonsäure

Heteroorganic Substances. IL. Reactions between N-morpholinosulfenylchloride and Ethane-alcoxy-thiophosphonous Acids and Ethane-ethyl-dithiophosphonic Acid The syntheses of bis-(ethane-alkoxy-thiophosphonyl)-monosulfides 3a – c and bis-ethane-ethoxy-thiophosphonyl)-trisulfide 5 are described. It is established, that the reaction path depends on the acidity of the starting compounds. In the first case (pK ∼ 7 the reactions between ethane-alkoxy-thiophosphonous acids and morpholinosulfenylchloride are three-step reactions, the intermediates being the unknown S-morpholino-ethane-alkoxy-dithiophosphonates 1a – c as well as the sulfenylchlorides of ethane-alkoxy-thiophosphonic acid 2a – c . In the second case (pK ∼ 3) a fourth reaction has to been taken into account. The intermediate sulfenamide derivatives are isolated and characterised. The sulfenylchlorides derivatives could not been isolated; their presence was indirectly demonstrated by chemical reactions.     

Epoxydationen mit Peressigsäure I: Zur Kenntnis der Peressigsäure und vergleichende Epoxydationen von Sojabohnenöl

Epoxidations with Peracetic Acid I: The Peracetic Acid and Related Epoxidations of Soybean Oil Progressive formation of peracetic acid by the action of hydrogen peroxide on acetic acid was studied. In the presence of ethyl acetate and by employing acetic anhydride, water free peracetic acid was obtained. In the epoxidation of soybean oil the maximum epoxide content of the same is dependent on the reaction conditions, especially on the degree of homogeneity of the reaction partners and the acidic catalyst.     

巯基乙酸的生产、应用与市场

介绍了巯基乙酸的生产方法、应用情况、市场需求状况。巯基乙酸的大规模生产方法是氯乙酸-硫氢化钠法,应用领域包括功能性化妆品、合成材料助剂和缓蚀剂等。2002年我国巯基乙酸的产量不超过600t,而需求量约为4500t,高纯度的巯基乙酸几乎全部依赖进口。2004年美国巯基乙酸的产量为1.24万t/a,西欧为1.4万t/a,日本为0.33万t/a。预计这些地区巯基乙酸的消费增长率在未来5年将保持为3%。     

Die Bestimmung der Erucasäure in Gegenwart von der Docosensäure

Determination of Erucic Acid in the Presence of Isomeric Docosenoic Acids In the countries belonging to the European Community the Erucic Acid Directive of 20. 7. 1976 restricts the level of erucic acid (not docosenoic acid) in edible oils and fats and foodstuffs to which fats and oils have been added to 5%. For the determination of the erucic acid content the EEC-Directive no. 80/891 specifies a procedure that enables the determination of erucic acid even in the presence of isomeric docosenoic acids. According to this procedure the methyl esters of fatty acids are first fractionated at –25°C on thin-layer plates containing silver nitrate. Thus, erucic acid (13-cis-docosenoic acid) is separated from isomeric docosenoic acids, such as cetoleic acid (11-cis-docosenoic acid) and trans-docosenoic acids, that are frequently found in crude and hydrogenated fish oils. The erucic acid content can be determined by gas chromatography of the eluted fractions after the addition of an internal standard. The method has been developed in collaboration with the Federal Center for Lipid Research. Their work concerned with the development of the method is reported. It includes the separation of pure docosenoic acid isomers and the determination of erucic acid content in a series of crude and hydrogenated fish oils.     

Zur Aminolyse von Bis-Imidoylchloriden der Oxalsäure. I. Umsetzung mit aromatischen und aliphatischen Aminen

On the Aminolysis of Bis-Imidoylchlorides of Oxalic Acid. Part I. Reaction with Aromatic and Aliphatic Amines The reaction between bis-imidoylchlorides 2 derived from oxalic acid and several aromatic and aliphatic amines was investigated. While primary aromatic amines need a thermical activation by refluxing, primary aliphatic amines give mainly at room temperature the amidines 3 in moderatly up to good yields. Proceeding from enantiomeric pure amines e.g. ( R )- or (S)-1-phenethylamine the new homochiral oxalic amidines 3y and 3z with C₂-symmetry were obtained. Several secondary amines react with the bis-imidoylchloride 2a to give via intramolecular cycloacylation derivatives of isatine. The new synthesized amidines 3 perform systems with a strong molecular dynamic like prototropie and E/Z-interconversion. All new compounds described were characterized by elemental analysis and spectroscopic methods.     

Synthese von Moosinhaltsstoffen. 8. Sphagnumsäure und ihre Abbauprodukte

Syntheses of Bryophyte Constituents. 8. Sphagnum Acid and its Degradation Products For Sphagnum acid ( 1 ) and its enzymatic degradation product 5-hydroxy-4-(4-hydroxyphenyl)-5H-furan-2-on ( 2 ) efficient syntheses on preparative scale were developed. For the (4-hydroxyphenyl)butenolide 2 some characteristic chemical transformations are observed in acidic and basic medium.     

Sulfochlorierung von 1,2-Naphthochinondiazid-(2) mit Chlorsulfonsäure

Sulfochlorination of 1,2-Naphthoquinone-(2)-diazide by Chlorosulfonic acid . The sulfochlorination of 1,2-naphthoquinone diazide-(2) ( 1 ) by chlorosulfonic acid was investigated. The yields of the formed products (1,2-naphthoquinone diazide-(2)-4-sulfonic acid ( 4 ), 1,2-naphthoquinone diazide-(2)-5-sulfonic acid ( 5 ), 1,2-naphthoquinone diazide-(2)-4-sulfochloride ( 2 ) and 1,2-naphthoquinone diazide-(2)-5-sulfochloride ( 3 )) depend on the temperature and on the time of reaction. The highest yields of the favoured 1,2-naphthoquinone diazide-(2)-4-sulfochloride ( 2 ) are obtained at 63°C and after a reaction time of 80 minutes (50%).     

4-叔戊基-2-(α-甲苄基)苯酚的合成

以对叔戊基苯酚和苯乙烯为起始原料,浓磷酸作催化剂,设计合成铷、铯萃取剂4-叔戊基-2-(α-甲苄基)苯酚。考察反应温度、反应时间、原料配比和催化剂用量为对4-叔戊基-2-(α-甲苄基)苯酚产率的影响。确定最佳反应条件为:反应温度140℃,反应时间3 h,n(苯乙烯)∶n(对叔戊基苯酚)=1.4,催化剂用量为对叔戊基苯酚质量的24.63%。此条件下,4-叔戊基-2-(α-甲苄基)苯酚产率为58.76%。     

Friedel-Crafts-Acylierungen aliphatischer Verbindungen. VII. Friedel-Crafts-Acylierungen von Carbonsäurechloriden mit Maleinsäureanhydrid - ein neuartiger Zugang zu Tetronsäuren

Friedel-Crafts-Acylations of Aliphatic Compounds. VII. Friedel-Crafts-Acylations of Carboxylic Acid Chlorides with Maleic Acid Anhydride — a New Access to Tetronic Acids Reaction of succinic acid with propionyl chloride under Friedel-Crafts-reaction conditions yields 2-methyl-cyclopentan-1,3-dione. The related reaction of maleic acid anhydride with propionyl chloride does not yield 2-methyl-cyclopent-4-en-1,3-dione 7 , but a E/Z-mixture of the lactones 5 and 8 . By treating with hydrogen chloride in methanol or with thionylchloride in methanol the lactone mixture is converted to dimethyl (2Z, 4E)-3-hydroxy-2-methyl-hexa-2,4-diendioate 10 . By reaction with excessive sodium hydroxide the mixture of lactones is transformed into tetronic acid 11 . Structure determinations are based on u.v.-, i.r.-, m.s.- and n.m.r.-spectroscopy and on further chemical transformations. This tetronic acid synthesis represents an intramolecular addition of a carboxylate anion to an α, β-unsaturated carbonyl compound.     

Synthesen auf der Basis von 2-Oxoglutarsäure. III [1] Synthese und Reaktionen von (E)-2-Oxoglutaconsäuredimethylester

Organic Syntheses Based on 2-Oxoglutaric Acid. III. Synthesis and Reactions of Dimethyl (E)-2-oxoglutaconate Dimethyl (E)-2-oxoglutaconate 1 obtained by dehydrobromination of dimethyl 3-bromo-2-oxoglutarate reacts with o-phenylendiamine to form the quinoxalin-2(1H)-one 2 , and with phenylhydrazine to yield the 4,5-dihydropyrazole 3 . Furthermore, a Doebner-von Miller-type reaction affords the 8-carboxy quinoline derivative 4 . Finally, addition of bromine leads diastereoselectively to the racemate of dimethyl 3S,4R- and 3R,4S-dibromo-2-oxoglutarate 5 .     

Stabilität von Ionenaustauschern gegen Salpetersäure und Bestrahlung. I. Nitrosierender Abbau der Iminodiessigsäuregruppen in Chelonaustauschern

The Stability of Ion Exchangers towards Nitric Acid and Radiation. I. Nitrosative Cleavage of the Iminodiacetic Acid Groups in Chelating Ion Exchangers The behaviour of the chelating ion exchangers Wofatit MC 50, Dowex A 1 and Chelex 100 with aminoacetic acid – and iminodiacetic acid-groups towards nitric acid in the range of the concentration 1…︁10,5 mol/l and at temperatures ⩽68°C was determined. It is found that the COOH capacity and the N content are rapidly reduced leading to the formation of CO₂ and N₂. If the exposure to HNO₃ continues there is again a rise in the COOH capacity. The i.r.- and mass spectra show that the iminodiacetic acid-groups are destroyed by nitrosative cleavage and CHO groups result, which are then oxidized to COOH groups. The mass spectrum shows that the aminoacetic acid-groups of the resin are nitrosated, which has also been confirmed by the use of nitric acid labelled with ¹⁵N.     

CdSe量子点的合成及其对潜指纹的荧光显现研究

以水热法在水相中直接合成了巯基乙酸修饰的CdSe量子点,并将合成的CdSe量子点进行表征、纯化。在波长365nm紫外光的激发下,CdSe量子点发射出明亮的黄绿色荧光,荧光发射峰约位于528nm,将得到的CdSe量子点纳米发光材料应用于非渗透性客体上潜指纹的荧光标记成像研究,发现CdSe量子点溶液显现的手印纹线流畅,显现细节特征明显,呈现明亮的黄绿色荧光指纹,具有很高的实用价值和鉴定价值。     

Synthese von Glutaconaldehyden aus Quadratsäure-Pyridiniumbetainen

Synthesis of Glutaconaldehydes from Pyridinium Betaines of Squaric Acid The pyridinium ring of squaric acid betaines ( 2 ) is opened by hydroxide ions. Electronegative substituents (RCl, CN) at C-3 promote this reaction. The stereochemistry of the resulting 5-(2-hydroxy-3,4-dioxocyclobut-1-en-1-yl)aminopenta-2,4-dienales ( 3 ) is confirmed by NMR-spectroscopy. Treatment of 3 with sodium hydroxide results in further hydrolysis to the sodium salts of glutaconaldehydes ( 5 ) and 3-amino-4-hydroxycyclobut-3-ene-1,2-dione ( 6 ). These products are also directly obtained from the nicotinic acid derivates 2 d (RCOOEt) and 2 e (RCONH₂), in the latter case cyclisation of the glutaconic acid derivate to the known 3-formylpyrid-2-one ( 10 ) is observed.