一锅法合成N-烯丙基-N-间氨基苯甲基-氨基甲酸叔丁酯

以间硝基苯甲醛和烯丙基胺为原料,通过还原胺化反应制得N-烯丙基-间硝基苄胺,然后实现了硝基还原和脂肪胺选择性保护一锅法进行,以57%的总收率合成了新化合物N-烯丙基-N-间氨基苯甲基-氨基甲酸叔丁酯。终产物结构经过IR、MS、1HNMR、13C NMR及元素分析确证。     

四苄基阿糖胞苷的合成

通过选用三苯甲基选择性保护阿拉伯糖5＇-位羟基、苄基保护4-位氨基和2’,3’-位羟基,于酸性条件下选择性脱除三苯甲基合成了制备阿糖胞苷5＇-位氨基酸酯类前药的关键中间体-四苄基阿糖胞苷,苄基保护基可经催化氢化顺利脱除。各步反应条件温和,收率高,操作简便。     

硼氢化钠/碘对3,5-二硝基苯甲酸甲酯的部分还原

采用硼氢化钠/碘体系选择性还原3,5-二硝基苯甲酸甲酯制备了3-氨基-5-硝基苯甲酸甲酯,收率达90%以上。该反应条件温和、操作简单、反应选择性高。     

1-[(4-氯苯基)苯甲基]哌嗪合成工艺改进

目的合成1-[(4-氯苯基)苯甲基]哌嗪并对工艺进行研究;方法以苯甲酰氯和氯苯为起始原料,经傅-克酰基化、还原、氯化、哌嗪缩合反应得到1-[(4-氯苯基)苯甲基]哌嗪;结果 1-[(4-氯苯基)苯甲基]哌嗪总收率为64.8%;结论工艺改进后,简化了反应操作,提高了反应收率。     

3,5-二羟基苯甲酸甲酯催化加氢制备3,5-二羟基甲苯

研究了用于3,5-二羟基苯甲酸甲酯加氢反应的催化剂,得到具有良好活性和选择性的CuO-ZnO催化剂。实验结果表明：采用Cu∶Zn原子比为1∶2、还原温度为200℃的CuO-ZnO催化剂,在反应温度200℃和压力9MPa条件下,反应时间1.6h,3,5-二羟基苯甲酸甲酯的转化率为100%,3,5-二羟基甲苯的收率达到87.4%。加氢反应历程的研究结果表明,3,5-二羟基甲苯的苯环易被加氢,生成带基团的环己烷系列副产物,使其收率下降,控制反应时间是提高反应收率的一个重要因素。     

1-O-甲基-3,5-二-O-(2,4-二氯苄基)-D-呋喃核糖合成研究

以D-呋喃核糖为原料,经羟基保护、选择性脱除2位保护基团,得到1-O-甲基-3,5-二-O-(2,4-二氯苄基)-D-呋喃核糖。以2,4-二氯氯苄作为羟基保护试剂,对羟基全保护反应进行了优化,产率达83.5%。选用四氯化锡作为脱苄试剂,选择性脱除2位苄基,产率达79.0%,总收率为66.0%。产物经质谱、核磁共振谱及红外光谱进行了结构表征。     

抗高血压药缬沙坦的新合成方法

以2N-三苯甲基-5-(4'-溴甲基联每2-基)四氮唑为原料,与L-缬氨酸甲酯盐酸盐反应制得N-[[2'-(2N-三苯甲基-四氮唑-5-基)-(1,1'-二苯基)-4-基]-甲基]-L-缬氨酸甲酯,然后经过脱三苯甲基保护、酰化、水解得到标题化合物,总收率49.8%.     

天然抗氧化剂紫檀芪的合成

以3,5-二甲氧基苯甲酸为原料,经还原、氯代、Arbuzov重排反应,得到中间体3,5-二甲氧基苄基磷酸酯,与二氢吡喃(DHP)保护的对羟基苯甲醛经过Witting-Horner缩合反应及脱保护合成天然抗氧化剂紫檀芪,总收率70.7%。中间体和目标化合物的结构用IR、MS和1H NMR进行了表征。此合成工艺原料价廉易得、合成步骤少、产率高,具有较好的工业应用前景。     

天然抗氧化剂紫檀芪的合成

以3,5-二甲氧基苯甲酸为原料,经还原、氯代、Arbuzov重排反应,得到中间体3,5-二甲氧基苄基磷酸酯,与二氢吡喃(DHP)保护的对羟基苯甲醛经过Witting-Horner缩合反应及脱保护合成天然抗氧化剂紫檀芪,总收率70.7%。中间体和目标化合物的结构用IR、MS和1H NMR进行了表征。此合成工艺原料价廉易得、合成步骤少、产率高,具有较好的工业应用前景。     

西替利嗪中间体1-[(4-氯苯基)苯甲基]哌嗪的合成

以4-氯二苯甲酮为起始物料通过还原、氯代、取代反应合成了左旋西替利嗪的关键中间体1-[(4-氯苯基)苯甲基]哌嗪,总收率达到67%。     

齐多夫定脱保护副产物的结构鉴定及其应用研究

采用FT-IR、MS、NMR等波谱技术对齐多夫定(AZT)脱保护副产物进行结构鉴定,确定了其结构为三苯甲基甲醚,并开发了其商业应用技术。在HCl作用下完成醚键断裂,把三苯甲基甲醚转化为三苯基氯甲烷,收率95.8%,该产物可再次应用到合成AZT的合成过程中,降低其生产成本。     

Formation of triphenylmethyl cation during the photolysis of phenylazotriphenyl methane: a laser flash photolysis study

The photolysis of phenylazotriphenyl methane (PAT) in dichloromethane and acetonitrile solution at λ_inc = 347nm and at 23°C results in the formation of triphenyl methyl (trityl) radicals and trityl ions. The quantum yields in dichloromethane solution are Φ(Ph₃C^•) = 0·060 and Φ(Ph₃C⁺) = 0·004. Trityl ions are assumed to be formed by electron transfer between radicals formed by the photodecomposition of PAT. The yield of trityl ions is significantly increased upon irradiation of PAT solutions containing also an onium salt (N-ethoxy-2-methyl pyridinium hexafluorophosphate; (EMP⁺PF₆^-). This is due to the oxidation of trityl radicals by EMP⁺ ions. Trityl ions generated in this way were found to be capable of initiating the cationic polymerization of cyclohexene oxide. © 1998 SCI.     

Homogeneous Tritylation of Cellulose in A Sulfur Dioxide – Diethylamine – Dimethyl Sulfoxide Medium

The present investigation was undertaken to see if a practical method could be developed for homogeneous tritylation of cellulose in a non-aqueous solvent of cellulose. Our new procedure of tritylation of cellulose can easily be carried out under homogeneous conditions by dissolving cellulose in a sulfur dioxide(SO₂)-diethylamine (DEA)-dimethyl sulfoxide(DMSO) solvent system, one or the non-aqueous cellulose solvents, followed by addition of trityl chloride and pyridine. This new method can avoid the time consuming pretreatment for the decrystallization of cellulose which has been necessary in the traditional procedure and can lower the reaction temperature. IR spectra of the products indicated the formation of trityl cellulose. Measurements of dielectric properties of the products confirmed that trityl groups were selectively introduced at the primary hydroxyl groups in cellulose. This conclusion was also confirmed by a H-NMR study in which the tritylated products was first acetylated, detritylated and then trideuterioacetylated and H-NMR spectra were taken at each stage and examined comparatively.     

Simultaneous construction of polymer backbone and side chains by terpolymerization. Synthesis of polyethers with the allyl side chains from dialdehydes, alkylene bis(trimethylsilyl) ethers, and allyltrimethylsilane

Polyethers with allyl side chains were synthesized by the simultaneous acid-catalyzed reaction of dialdehydes (1), alkylene bis(trimethylsilyl) ethers (2), and allyltrimethylsilane (3). The reactions of 1, 2 and 3 were carried out in the presence of 10 mol% of triphenylmethyl (trityl) perchlorate at −55°C to yield polyethers having allyl groups in the side chains. When the dialdehyde having the ester moieties as 1, ethylene bis(trimethylsilyl) ether and 1,4-bis(trimethylsiloxy)cyclohexane as 2 were used, high molecular weight polymers were obtained. In the polymerizations at ambient temperature, the polymer was precipitated during the reaction because of crosslinking between the aromatic rings via a trityl perchlorate assisted Friedel-Crafts reaction. The soluble polyether with the allyl side chains reacted with 1,2-ethanedithiol in the presence of a radical initiator in benzene at 60°C to yield a crosslinked polymer quantitatively within 1 h. This polymer synthesis is unusual in that it concurrently constructs both the polymer backbone and the functional side chains from three monomers.     

两种对氨基酚生产扑热息痛的收率对比

文章介绍了铁粉法和加氢法两种不同工艺生产的对氨基酚在工业化装置上生产扑热息痛时的收率情况,讨论了配料酸度、产品纯度、酸母液套用次数、活性炭用量等因素对收率的影响;通过对比,说明了加氢法对氨基酚在收率、母液套用、废水削减等方面较铁粉法对氨基酚具有技术优势,也使扑热息痛综合生产成本更低,更既有利于市场竞争。     

An improved procedure for the detritylation of 1-alkyl 2-acyl 3-trityl-sn-glycerols

The effects of experimental conditions and acid catalysts on the removal of the trityl group of 1-alkyl-2-acyl-3-trityl-sn-glycerols to yield 1-alkyl-2-acyl-sn-glycerols have been investigated. Removal of the trityl protecting group was complicated by the concomitant migration of the 2-acyl moiety to yield the 1-alkyl-3-acyl-sn-glycerol isomer. The course of detritylation as well as the extent of the 2-acyl to 3-acyl migration under the various conditions used were followed by high performance liquid chromatography (HPLC). Optimum yields of the desired 1-alkyl-2-acyl-sn-glycerol (}90%) were obtained with a molar equivalent of boron trifluoride-methanol in methylene chloride at 22 C for five min. Presented in part at the AOCS meeting in Honolulu, Hawaii, in May 1986.     

Living radical polymerization in homogeneous system with phenylazotriphenylmethane as a thermal iniferter

Summary Radical polymerization of methyl methacrylate (MMA) with phenylazotriphenylmethane (PAT) was found to give the polymer with a trityl group bonded at its -chain end which could further dissociate into propagating and trityl radicals. Therefore, it was confirmed that PAT served as a thermal iniferter for polymerization of MMA, which proceeded via a living radical mechanism, i.e. yield and molecular weight of the polymers increased with reaction time. When the polymer thus obtained was used as a polymeric iniferter for the polymerization of styrene (St), the block copolymer was obtained.     

硫磺在1-氨基蒽醌还原中的应用

1-氨基蒽醌是蒽醌系列中间体中最为重要的品种之一,主要用于染料及染料中间体的合成,其生产方法是以蒽醌为原料,经硝化、精制、还原得到产品,目前工业生产全部采用硫化钠还原工艺,其投资少,操作简单,得到的产品质量优良,还原产生的含硫废水经处理后用于制备硫代硫酸钠副产品,少量有机废渣经焚烧处理后基本可以作到清洁生产,但是由于硫化钠呈强碱性,高温还原时使得部分硝基蒽醌水解,对产品收率有一定影响,加入硫磺后不但可以有效降低介质碱度,而且还可大幅度减少硫化钠用量,在提高收率的同时还降低了还原剂成本,减少了还原废渣。     

两种工业合成单硅烷的工艺介绍

单硅烷(SiH4)作为一种提供硅组分的气体源,可用于制造多种高纯度晶体硅、非晶硅、氮化硅、氧化硅及金属硅化物,详细介绍了硅化镁法和还原法制备SiH4的工艺。硅化镁法的优点是工艺简单、成熟,原料易得;其缺点是分离和回收液氨时能耗大,SiH4收率相对较低。还原法的优点是可实现连续化生产、反应易于控制。     

基于粗糙集的智能可视化优化方法用于加氢裂化反应操作优化

加氢裂化反应的历史生产数据包含了丰富的操作规律,而目前没有被充分挖掘和利用。针对该问题,本文 提出了基于粗糙集的智能可视化优化方法,并应用该方法对加氢裂化反应的操作变量进行了优化。采用自适应离 散化的方法对加氢裂化反应的生产操作数据进行离散化,得到离散化的数据集。针对数据集属性约简的N-P 难题, 提出了基于列队竞争算法的属性约简计算方法。通过对加氢裂化反应的数据集约简计算,使预设的12 个操作变量 约简到了8 个,除去了4 个冗余变量,有效降低了优化搜索空间。在此基础上,应用智能可视化优化方法将约简 后的加氢裂化反应数据降维映射到平面,并生成航煤收率的等值线,据此,直观地确定出了航煤收率的优化区域 和优化操作点。结果说明,选出的优化工况点与原工况航煤收率33.98%相比,能使航煤收率提高到37.58%.