顺-5-降冰片烷-外-2,3-二甲酰亚胺的合成

以顺-5-降冰片烯-外-2,3-二甲酸酐（2）为原料,氨气为氨源,经氨化反应制得顺-5-降冰片烯-外-2,3-二甲酰亚胺（3）; 3经钯炭催化氢化合成了盐酸鲁拉西酮关键中间体顺-5-降冰片烷-外-2,3-二甲酰亚胺（1）,其结构经¹ H NMR和MS（ESI）确证。研究了2与氨气的投料比[r=n（2）/n（氨气）]、反应时间、析晶时间对3外观和收率的影响,以及氢化反应温度和反应时间对1外观和收率的影响。结果表明：合成3的最佳反应条件为：r=1.0/2.5,反应时间25~30 h,析晶时间6~8 h, 3收率93.2%。合成1的最佳反应条件为：氢化反应温度20~30 ℃,反应时间6~10 h, 1收率98.2%。 1的中试极限条件为：于40~50 ℃浓缩6 h,湿品于45~55 ℃干燥8 h,总收率91.5%。     

国产阴树脂在柠檬酸精制中的应用研究

钙盐法提取柠檬酸,在其溶液中含SO_4~(2-)2000～3200ppm,我们采用国产阴树脂CR—1,在空速4.2hr~(-1)、pH1.7～2.0、温度25℃～35℃条件下,交换后柠檬酸溶液中SO_4~(2-)含量小于5ppm,柠檬酸收率为98.68％。     

2-吲哚酮和5-甲基-2-吲哚酮的无溶剂法制备

以苯胺和氯乙酰氯为原料在NaOH存在下酰化合成N-氯乙酰基苯胺,然后N-氯乙酰基苯胺在无水AICI,催化下环化合成2-吲哚酮．对由N-氯乙酰基苯胺合成2-吲哚酮的工艺条件进行了改进．结果表明合成2-吲哚酮的最佳条件为：反应温度为220℃,反应时间为60min,加料时温度为180℃,N-氯乙酰基苯胺与氯化钠,无水AlCl3的重量比为1：1：5．5．改进后的合成2-吲哚酮收率达到88．3％,纯度99％,收率比原工艺提高了24．6％．在此基础上,还合成了5-甲基-2-吲哚酮,并得到其最佳条件为：反应温度为190℃,反应时间为30min,加料时温度为180℃,4-甲基-N-氯乙酰基苯胺与氯化钠,无水AlCl3的重量比为1：1：5．5,收率达到83．1％,纯度为99％．     

水蒸气处理对P-ZSM-5催化性能的影响

在不同温度下,用水蒸气对P-ZSM-5催化剂进行了处理,利用XRD、NH3-TPD、比表面和孔径物理吸附仪等手段对催化剂进行了表征,研究了水蒸气处理对P-ZSM-5催化1-丁烯裂解反应性能的影响.实验结果表明:P-ZSM-5催化剂具有良好的水热稳定性;合适的水蒸气处理,有利于催化剂孔容和孔径的增加;水蒸气处理降低了P-ZSM-5催化剂的酸量和酸强度,明显提高了丁烯裂解生成丙烯的选择性、收率和催化剂的抗积炭性能.最佳的水蒸气处理温度为580℃,P-ZSM-5催化剂催化1-丁烯裂解反应的丙烯选择性为39.4%,收率为34.2%.     

低硅铝比ZSM-5分子筛上C4烃的催化裂解反应

以低硅铝比(n(SiO2)/n(Al2O3)=20-45)的ZSM-5分子筛为催化剂, 研究了混合C4烃的催化裂解反应, 并对不同硅铝比的ZSM-5分子筛进行了酸性表征. 混合C4烃的催化裂解反应结果表明, 低硅铝比的ZSM-5分子筛具有较高的低温催化活性, 高硅铝比ZSM-5分子筛催化剂上乙烯和丙烯的收率高于低硅铝比ZSM-5分子筛催化剂, 低硅铝比ZSM-5分子筛上苯和甲苯的收率高于高硅铝比ZSM-5分子筛催化剂. 在反应温度为625 ℃时, 硅铝比为20的ZSM-5分子筛催化剂上乙烯、丙烯、苯和甲苯的总收率可达79.42%. 酸性表征结果表明, 硅铝比低的ZSM-5分子筛具有更多的Bronsted(B)酸酸量、Lewis(L)酸酸量及总酸酸量, 这是低硅铝比ZSM-5分子筛具有低温高活性及高的苯和甲苯收率的原因.     

低硅铝比ZSM-5分子筛上C4烃的催化裂解反应

以低硅铝比(n(SiO2)/n(Al2O2)=20-45)的ZSM-5分子筛为催化剂,研究了混合C4烃的催化裂解反应,并对不同硅铝比的ZSM-5分子筛进行了酸性表征.混合C4烃的催化裂解反应结果表明,低硅铝比的ZSM-5分子筛具有较高的低温催化活性,高硅铝比ZSM-5分子筛催化剂上乙烯和丙烯的收率高于低硅铝比ZSM-5分子筛催化剂,低硅铝比ZSM-5分子筛上苯和甲苯的收率高于高硅铝比ZSM-5分子筛催化剂.在反应温度为625℃时,硅铝比为20的ZSM-5分子筛催化剂上乙烯、丙烯、苯和甲苯的总收率可达79.42%.酸性表征结果表明,硅铝比低的ZSM-5分子筛具有更多的Bronsted(B)酸酸量、Lewis(L)酸酸量及总酸酸量,这是低硅铝比ZSM-5分子筛具有低温高活性及高的苯和甲苯收率的原因.     

硼酸催化三组分无溶剂“一锅法””合成5-[(3-吲哚基)-甲基]-2,2-亚丁基-1,3-二噁烷-4,6-二酮衍生物

在硼酸催化下,以吲哚、醛和2,2-亚丁基-1,3-二噁烷-4,6-二酮为原料,经三组分无溶剂条件合成了9种5-[(3-吲哚基)-甲基]-2,2-亚丁基-1,3-二噁烷-4,6-二酮衍生物.当催化剂的用量为5 mol%时,60℃反应30~90 min,收率为68.6%~91.3%.此外,还探讨了硼酸可能的催化机理.该方法具有反应条件温和,反应时间短且收率高的优点.硼酸催化剂对环境友好且可循环利用.     

氧化石墨烯催化果糖-氯化胆碱低共熔物脱水制5-羟甲基糠醛

研究了氧化石墨烯(GO)催化果糖-氯化胆碱低共熔物脱水制取5-羟甲基糠醛(5-HMF)的反应过程。采用改进的Hummers法制备GO,通过FT-IR、XRD和SEM等手段对GO结构进行了表征。考察了原料量、催化剂量、反应温度和时间等对5-HMF产物收率的影响。结果表明:果糖与氯化胆碱形成低共熔溶剂提高了果糖与GO的接触效率,脱水速率显著提高;在温度110℃,反应时间4h,GO与果糖质量比为1∶50的条件下,5-HMF液相色谱收率达到74. 5%,几乎没有检测到副产物。GO分子中的羧基基团担负着果糖的脱水过程。GO循环使用六次,仍具有较好的催化效果,5-HMF收率基本不变,说明GO重复使用性能良好。     

N-取代-5-氧代吡咯烷-3-甲酸化合物的合成

本文以衣康酸二甲酯为原料,分别和3种脂环胺发生Michael加成反应,得到3种N-取代-5-氧代吡咯烷-3-甲酸甲酯(2a～2c),再经碱性条件下水解得到3种N-取代-5-氧代吡咯烷-3-甲酸(1a～1c)。目标化合物及中间体结构通过~1H NMR、~(13)C NMR和ESI-MS确证。同时,以衣康酸二甲酯与环丁胺的Michael加成反应为模型,确定该步的优化反应工艺为:物料摩尔比n(环丁胺)∶n(衣康酸二甲酯)=1.3∶1,甲苯作溶剂,110℃反应2h。在该反应条件下,化合物2b收率为91.2%,其结构进一步通过X-射线单晶衍射确证。     

Ru助剂对Co/SiO_2/HZSM-5催化剂合成航空燃油类烃的影响

以中孔硅胶和微孔HZSM-5分子筛为复合载体,添加Ru制备了钴基催化剂,考察了Ru添加量(1%~4%,质量分数)对催化剂结构和固定床费托合成航空燃油类烃的影响。实验结果表明,制备的复合载体催化剂有一定的微孔和中孔结构,Ru的添加有利于Co分散,Ru促进的催化剂低温还原过程提高了催化剂在150~750℃的还原度和CO转化率,复合载体中HZSM-5分子筛利用其微孔结构,提高了异构烃的收率。当Ru负载量为1%时,CO转化率达到62.8%,航空燃油类烃的收率达到37.7%,包括约10.9%的异构烃。Ru负载量超过2%时,增强的催化剂CO加氢活性和CH4选择性,导致合成产物向低碳烃方向偏移。     

Mass spectra of 5-styryl and 5-acylpyrazoles

High-resolution, electron-impact, mass-spectrometric measurements have been made on three types of pyrazoles. Type 1 comprised ethyl 5-styrylpyrazole-3-carboxylates having in the α-position of the styryl group either a hydrogen atom, a methyl, or a phenyl group. Type II were 1,3,5-trisubstituted pyrazoles having phenyl (or p-substituted phenyl) groups in position 1, amide or carboxylate groups in position 3, and styryl (or α-substituted styryl) groups in position 5. Type III differed from type II in possessing a readily cleaved acyl or aroyl group instead of the styryl group. The compounds containing styryl groups gave significant ions corresponding to the formation of polycyclic heteroaromatic rings, in addition to various other fragments derived from such rings. Intensities and accurate mass-measurements are given for all ions having intensities exceeding 5% of the base peak.     

Conversion of 5-hydroxy to 5-amino and 5-alkoxypyrazolidines

1-Acyl-5-hydroxypyrazolidines readily exchange their hydroxyl group when treated with primary amines or alcohols to form the corresponding 5-amino or 5-alkoxypyrazolidines. An acid catalyst is needed for the preparaton of the 5-alkoxypyrazolidines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 484–487, April, 1987.     

Improved synthesis and mutagenicity of oligonucleotides containing 5-hydroxymethylcytosine, 5-formylcytosine and 5-carboxylcytosine

5-Formylcytosine (fC or (5-CHO)dC) and 5-carboxylcytosine (caC or (5-COOH)dC) have recently been identified as constituents of mammalian DNA. The nucleosides are formed from 5-methylcytosine (mC or (5-Me)dC) via 5-hydroxymethylcytosine (hmC or (5-HOMe)dC) and are possible intermediates of an active DNA demethylation process. Here we show efficient syntheses of phosphoramidites which enable the synthesis of DNA strands containing these cytosine modifications based on Pd(0)-catalyzed functionalization of 5-iododeoxycytidine. The first crystal structure of fC reveals the existence of an intramolecular H-bond between the exocyclic amine and the formyl group, which controls the conformation of the formyl substituent. Using a newly designed in vitro mutagenicity assay we show that fC and caC are only marginally mutagenic, which is a prerequisite for the bases to function as epigenetic control units.     

5-Ethylthiomethyl- und 5-Ethylsulfonylmethylpyrimidine

In 2,4-dichloro-5-ethylthiomethylpyrimidines3a, b and in (2,4-dichloro-5-pyrimidinylmethyl)ethyl sulfones5a, b, resp., by reaction with ammonia, diethyl-amine, isopropylamine, sodium methanolate and sodium ethylthiolate, resp., the halogen atoms have been substituted by amino, methoxy or ethylthio groups, resp., and thus the compounds4a–4r and5c–5f have been obtained.

     

Umlagerung von 5-Amino-5-X-pentadienalen zu 2-Aminopyrylium-Salzen

Rearrangement of 5-Amino-5-X-pentadienals to 2-Aminopyrylium Salts Various 2-aminopyrylium salts 7 (X=Cl, Br, I) are available in a simple one-pot procedure by reacting `push-pull' enynes 5 with equivalent amounts of HCl, HBr, or HI. On the other hand, reaction of HF or AcOH with `push-pull' enynes 5 is considerably slower so that an excess of HF or AcOH is needed for the reaction to 7 (X=F, AcO). The 2-aminopyrylium salts 7 are the key intermediates in the postulated rearrangement of 5-amino-5-halogeno-pentadienals 6 to 5-halogenopenta-2,4-dienamides 8 (Scheme 1, bottom), which is vinylogous to the well-known rearrangement of 3-amino-3-X-propenals 2 to 3-X-propenamides 3 (Scheme 1, top).     

Synthesis of 5-dialkylaminothiocarbonylthiobarbituric acids and 5-diethyiaminothiocarbonylthio-6-aminouracil

The title compounds are obtained by three different methods. The aminothiocarbonylthiolation of barbituric acids 1 and aminouracil ( 5 ) can be accomplished in one step by reaction with thiuram disulfides in the presence of potassium carbonate. On the other hand, compounds 4 can be obtained via the salt of chloro derivative 2 or the corresponding iodonium ylides 3 . The aminouracil derivative 7 was obtained in a similar fashion from 5 directly or via iodonium betaine 6 .     

Synthesis and photoreactivity of some 5-alkylidene- and 5-alkylidenamine-2,5-dihydroisoxazoles

5-Alkylidene-2,5-dihydroisoxazoles and 5-alkylidenamine-2,5-dihydroisoxazoles were easily prepared from the corresponding 5-chloro-2-methylisoxazolium triflate and an enolizable compound or alkylamine. Their photochemical reactivity leads to photoisomers that in some cases constitute new heterocycles systems. The photorearrangement involves either triplet or singlet state depending on substituents and experimental conditions.     

Substituted 5-aryl- or 5-diphenylmethyl-3-alkyl-2-oxazolidones as anticonvulsants

Several 5-aryl- or 5-diphenylmethylhydracrylyl hydrazides were synthesized and converted into 5-aryl- or diphenylmethyl-2-oxazolidones. The latter compounds were further alkylated into their corresponding 5-aryl- or 5-diphenylmethyl-3-alkyl-2-oxazolidones as possible anticon-vusants.     

New synthesis of 5-amino-5-deazaflavin derivatives by direct coupling of 5-deazaflavins and amines

5-Amino-5-deazaflavin derivatives are newly synthesized by direct coupling of 5-deazaflavins and amines. Some of them revealed potential activity toward tumor cells such as L1210 or KB cells.     

Some Observations Concerning 1H-NMR. Spectra of 5-hydroxy- and 5-acetoxy-steroid compounds

It was found that analysis of the ¹H-NMR. signals (at 360 (preferably) and/or 100 MHz) of the protons at C (4) and of the equatorial α-proton at C (6), particularly when these are located in the 2–3 ppm region and therefore convenient for detection and identification, may be of valuable aid in the structural and configurational characterization of 5-hydroxy- and 5-acetoxy-steroids (unsubstituted or containing a hydroxy or acyloxy substituent at C (3)).