4-羟基吡啶的合成工艺进展

分别介绍了以草酸二乙酯、丙酮、氨气为原料经缩合、水解、氨化和热解反应合成4-羟基吡啶;以吡啶、氯化亚砜为起始原料经氯化和水解反应合成4-羟基吡啶;以4-氨基吡啶为起始原料经重氮和水解反应合成4-羟基吡啶;并对这些合成路线进行了探讨.     

4—氨基—2—氯吡啶的合成研究

在对４－氨基－２－氯吡啶合成路线进行分析评价的基础上，以２－氯吡啶－Ｎ－氧化物为起始原料，经过硝化和还原两步反应，者了以工业化为目的的合成研究，产品总收率达到５６％。     

2－氯－4－氨基吡啶的合成

以２－氨基吡啶为原料，经乙酰化，Ｎ－氧化，水解，Ｓａｎｄｍｅｙｅｒ反应，硝化和催化氢化合成２－氯－４－氨基吡啶。     

4-氨基-2-氯吡啶的合成研究

在对４－氨基－２－氯吡啶合成路线进行分析评价的基础上,以２－氯吡啶－Ｎ－氧化物为起始原料,经过硝化和还原两步反应,进行了以工业化为目的的合成研究,产品总收率达到５６％ 。     

4—苯氧基吡啶的合成

在对合成4－苯氯基吡啶两种路线对比的基础上,以吡啶,氯化亚砜,苯为原料首先合成4－吡啶基－吡啶氯化物盐酸盐,然后加入氢氧化钠,二氯化锌合成4－吡啶氯化锌,再加入苯酚合成4－苯氧基吡啶进行了实验,并对实验结果进行了讨论。     

2—氨基—5—甲基吡啶的合成

本文介绍了以３－甲基吡啶为起始原料,经三种途径合成２－氨基－５－甲基吡啶的方法。并对其中一种合成方法及操作制备步骤进行了详细介绍。     

4-乙酰氨基环己酮

以4-氨基环己醇为原料，经酰化、氧化两步反应，合成了医药中间体4-乙酰氨基环己酮，研究了反应条件及影响因素，确定了以4-氨基环己醇为原料，经氨基乙酰化Jones试剂氧化的合成工艺路线，所合成的产品为白色粉末状晶体，熔点130-135℃。合成工艺的反应条件温和适合工业生产。     

马来酸氟吡汀的合成研究

以6-硝基-2,5-二氨基吡啶和4-氟氯苄为起始原料经缩合得2-硝基-3-氨基-6-(4-氟苄胺基)吡啶,再经过氯化钙和硼氢化钠组合还原得到2,3-氨基-6-(4-氟苄胺基)吡啶,再与氯甲酸乙酯进行酰化反应,得到氟吡汀,再与马来酸成盐得到马来酸氟吡汀。此合成路线以6-硝基-2,5-二氨基吡啶和4-氟氯苄为原料,以氯化钙和硼氢化钠代替重金属催化氢化,具有较高安全性,较高收率,总收率为63.6%。     

2,3-二氨基吡啶的合成研究

氨基吡啶类化合物是重要的有机化工原料,是合成许多精细化学品的中间体,在农药、医药、高分子及含能材料等领域有广泛的应用。对氨基吡啶类化合物的合成研究非常有意义。文章介绍了标题化合物的合成方法。以2,6-二氯吡啶为起始原料,经硝化、氨基取代、还原3步反应合成了目标化合物,并经MS和~1H NMR对其结构进行了表征。本合成路线原料廉价易得、反应条件温和、操作方便,是一种适合于工业化生产的新方法。反应的总收率57%。     

N-(4-吡啶基)-2-羟基苯甲酰胺的合成工艺研究

首次以水杨酸为原料,与4-氨基吡啶反应合成了标题化合物,实验考察了不同的反应条件对产品收率的影响,得出最佳反应条件为:7 mmol 4-氨基吡啶、8.4 mmol水杨酸酰氯、11 mL三乙胺,25℃反应18 h,产品收率为87.8%。本合成路线反应条件温和、工艺操作简便、容易控制。     

碘催化Gr(o)ebke反应合成3-氨基咪唑并[1,2-a]吡啶衍生物

以芳香醛、2-氨基吡啶和异腈为原料,10 mol％分子碘作催化剂,甲醇作溶剂,回流反应3h合成标题化合物.该反应条件温和,产率为76％ ～90％,相应的结构经过红外、核磁共振和质谱表征确认.     

多孔陶瓷粒子电极电催化氧化降解2-氨基吡啶

采用以CuO-ZnO/多孔陶瓷粒子电极构建的三维电催化氧化反应器降解2-氨基吡啶,考察了初始pH值、槽电压、电解质投加量和曝气流速对降解效果的影响和反应的电流效率,并通过检测2-氨基吡啶降解过程中几种含氮产物,分析了2-氨基吡啶的降解过程。结果表明：酸性条件和碱性条件比中性条件更有利于2-氨基吡啶的降解,在初始pH值为8.4、槽电压为15 V、支持电解质用量为30 g/L、曝气流速为40 L/h的条件下,处理150 min,2-氨基吡啶和COD的去除率可分别达到83.98%和74.44%,粒子电极可以显著提高电流效率。2-氨基吡啶降解过程分析表明：在电催化条件下,N2和NO3?-N是2-氨基吡啶主要含氮矿化产物,且2-氨基吡啶的开环转化和矿化可以同步进行。     

4-氨基吡啶的合成技术进展及其应用

评述了4-氨基吡啶的合成研究进展,重点介绍了硝基氮氧化吡啶法工艺。概括介绍了4-氨基吡啶在医药、农药、染料等领域的应用状况以及在国内外的生产现状。指出4-氨基吡啶合成工艺的难点在于降低生产成本,提高反应收率以及减少环境污染。建议从催化加氢还原或电化学还原过程中找到一条合乎国情的工艺路线,以推动我国吡啶系列产品的研发工作。     

Binary freezing-point diagrams for palmitic acid with various amines and with 2,6-dimethyl-gamma-pyrone

Summary In connection with the search for molecular compounds which might prove applicable in the purification of long-chain fatty acids, freezing-point data have been obtained for binary systems between palmitic acid and the following: ortho-phenylenediamine, alpha-picoline, 4-amino-2,6-dimethylpyrimidine, 2,6-dimethyl-gamma-pyrone, 2-aminothiazole, benzylamine, morpholine, 3-aminopyridine, and 4-aminopyridine. The freezing-point diagrams for the first four of these binary systems are of the simple eutectic type. All the others indicate the existence of at least one crystalline molecular compound containing one or more moles of palmitic acid to one of amine. 2-Aminothiazole forms an equimolar compound. Both benzylamine and morpholine form an equimolar and an incongruently melting 2∶1 compound. The position of the amino group in the pyridine ring has a marked effect on the behavior of the aminopyridines. Unlike 2-aminopyridine, which forms a 1∶1 and a 4∶1 compound with palmitic acid, 3-aminopyridine forms only an equimolar compound and 4-aminopyridine forms only 4∶1 and 2∶1 compounds. The latter exists in two polymorphic modifications. One of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Modification of the adsorptive properties of charcoal by treatments with pyridines

Studies on the use of various pyridines (e.g., pyridine, 4-vinylpyridine, 4-aminopyridine, 4-cyanopyridine, and 4-n-propylpyridine) to modify the adsorptive properties of charcoal are described. The impregnated charcoals are compared with respect to adsorption capacity for carbon tetrachloride and cyanogen chloride under dynamic conditions and relative affinity for methyl iodide under equilibrium conditions. In several cases, the effect of impregnant concentration and method of impregnation were examined in detail. As part of the overall study, it was interesting to find that adsorption of 4-vinylpyridine resulted in the formation of ethanol intractable material (presumably polymer) on the surface of the charcoal which still exhibited chemical reaction activity. It would appear that adsorption of 4-vinylpyridine results in polymerization with a molecular orientation which allows pyridine nitrogens to be available for chemical reactivity. A charcoal prepared by adsorption of poly-4-vinylpyridine showed little chemical reactivity.     

β-硝基四苯基卟啉锌的合成及其光谱性质

合成了β-硝基四苯基卟啉[H2TPP（NO2）]及其锌配合物[ZnTPP(NO2)],用元素分析、红外光谱、电子吸收光谱等手段对其组成和结构进行了表征。研究了吡啶4-甲基吡啶、4-甲基吡啶、4-氨基吡啶、4，4-联吡啶、咪唑、1-甲基咪唑、2-甲基咪唑等化合物对ZnTPP(NO2）电子光谱的影响，结果表明，ZnTPP(NO2)溶液中加入吡啶类和咪唑类化合物后，ZnTPP(NO2)的电子光谱发生变化是由于ZnTPP(NO2）与吡啶类和咪唑类化合物发生轴向配位反应而生成加合物的缘故。     

Characterization and Electrical Properties of Some Hydrochloric Acid-Doped Aniline and 2-Amino-Pyridine Homopolymers and Copolymers

The synthesis of (group I) hydrochloric acid-doped poly(aniline-co-toluidine), poly(aniline-co-thiophene), poly(aniline-co-o-phenylenediamine), and poly(aniline-co-2-aminopyridine) as well as their hydrochloric acid-doped homopolymers of polyaniline, poly-m-toluidine, poly-o-phenylene diamine, and poly-2-aminopyridine and the synthesis of (group II) hydrochloric acid-doped poly (2-aminopyridine-co-o-phenylene diamine) and its hydrochloric acid-doped homopolymers of poly 2-amino pyridine and poly-o-phenylene diamine have been carried out via a chemical oxidation process using ammonium and potassium persulphate as chemical initiators. The synthesized homo- and copolymers were characterized by ultraviolet-visible spectroscopy (UV-VIS), infrared spectroscopy (IR), and thermal analysis. The variation of the electrical conductivity (σ, S cm^?1) with the reciprocal of the absolute temperature (1000/T, K) at different frequencies (1–1000 kHz) for hydrochloric acid homopolymers and copolymers is illustrated.     

Metal ion functional polybenzoxazine based on phenol and 2-aminopyridine

A novel Co²⁺ ion functional benzoxazine monomer based on phenol and 2-aminopyridine was prepared, polymerized by step-wise curing and characterized via direct pyrolysis mass spectrometry in addition to classical spectrometry techniques. Curing of neat monomer yielded a highly cross-linked polymer as a consequence of competing and consecutive reactions involving the heterocyclic ring opening followed by attack of –NCH₂ groups to ortho and para positions of phenol and pyridine rings and coupling of –NCH₂ groups. On the other hand, the coordination of metal ion to nitrogen atoms of the pyridyl rings inhibited the attack of –NCH₂ groups to ortho and para positions of pyridine rings and eventually decreased the extent of cross-linking.     

Graft copolymerization of 4-vinyl pyridine onto isotactic polypropylene hydroperoxide by mutual irradiation method

An attempt has been made to graft copolymerize 4-vinyl pyridine onto isotactic polypropylene hydroperoxide by mutual irradiation method in an aqueous medium. Polypropylene hydroperoxide has been prepared by irradiating recrystallized polypropylene beads from a Co⁶⁰ source in the presence of air. The resulting polypropylene hydroperoxide beads have been used as the backbone polymer and grafting of 4-vinyl pyridine has been studied as a function of various reaction parameters. Optimum conditions for maximum percentage of grafting have been evaluated. Rate of grafting (R_g) has been determined as a function of preirradiation dose and initial monomer concentration. Water has been found to affect percentage of grafting. The graft copolymers have been characterized by spectroscopic method and isolation of the grafted poly(4-VP) from the graft copolymer. A plausible mechanism is proposed to explain the mutual grafting of 4-vinyl pyridine onto polypropylene hydroperoxide. © 1993 John Wiley & Sons, Inc.