Phenoxyhydroxypropylhydroxyethylcellulose—new amphiphilic cellulose derivative

A new amphiphilic cellulose derivative phenoxyhydroxypropylhydroxyethylcellulose of substitution degree up to 0.67 was synthesized by reaction of water-soluble hydroxyethylcellulose with 2,3-epoxypropylphenylether in the presence of sodium hydroxide as a catalyst. The chemical composition of the derivative was confirmed by means of UV, IR- and ¹³C-NMR-spectroscopy. The derivatives with substitution degree up to 0.12 are soluble in water and water–alcohol mixtures. With increasing substitution degree, the polymers lose their water solubility, but still dissolve in water–alcohol mixtures. All products are soluble in aprotic solvents. The effect of the reaction conditions, such as temperature and molar ratios of reaction components, on both the reaction rate and degree of substitution was investigated.     

Novel Regioselectively 6‐Functionalized Cationic Cellulose Polyelectrolytes Prepared via Cellulose Sulfonates

The synthesis of new 6‐deoxy‐6‐trialkylammonium cellulose derivatives obtained by nucleophilic displacement reactions of p‐toluenesulfonyl celluloses with various amines is described. Water soluble cellulosics could be prepared using a N,N‐dimethylformamide/water mixture as the reaction medium. Detailed studies concerning the influence of reaction time and temperature as well as the water content on the solubility of the products were carried out. Even the synthesis of large sample amounts was possible using optimized reaction conditions. The 6‐deoxy‐6‐trialkylammonium cellulose derivatives are water‐soluble even at low degrees of substitution, i. e., in the range of 0.2 and 0.5. The structure was confirmed by means of ¹H and ¹³C NMR spectroscopies.     

Synthesis and characterization of cellulose derivatives prepared in NaOH/urea aqueous solutions

We successfully synthesized hydroxypropylcellulose (HPC) and methylcellulose (MC) in high yields from cellulose in 6 wt % NaOH/4 wt % urea aqueous solutions at 25 °C. The cellulose derivatives were characterized with NMR, size exclusion chromatography/laser light scattering, gas chromatography (GC), ultraviolet, and solubility measurements in different solvents. According to the results of solution ¹³C NMR and GC, the individual degree of substitution (DS; i.e., the average number of substituted hydroxyl groups in the monomer unit) at C‐2 hydroxyl groups was slightly higher than the DS values at C‐3 and C‐6 hydroxyl groups for HPC and MC. In comparison with traditional systems, NaOH/urea aqueous solutions were proved to be a stable and more homogeneous reaction medium for preparing cellulose ether with a more uniform microstructure. The low limits for the average number of moles of the substituent groups per monomer unit and the DS value of water‐soluble HPC were 1.03 and 0.85, respectively. MC (DS = 1.48) had good solubility in both water and organic solvents, and the precipitation point occurred at about 67 °C for a 2% (w/v) aqueous solution. In this way, we could provide a simple, pollution‐free, and homogeneous aqueous solution system for synthesizing cellulose ethers. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5911–5920, 2004     

对甲基苯磺酸亚铈催化一锅法合成取代2,3-二氢-4(1H)-喹唑啉酮

以对甲基苯磺酸亚铈为催化剂,靛红酸酐、醛和铵盐或伯胺为原料,在乙醇水溶液中三组分一锅法合成了一系列单取代和双取代2,3-二氢-4(1H)-喹唑啉酮衍生物。考察了溶剂条件及催化剂用量对产率的影响。经催化剂循环研究,催化活性无明显变化。产物的结构通过熔点、IR、1H NMR、13C NMR、质谱和元素分析进行测定和结构表征。     

Recent advances in molecuar and supermolecuar characterization of cellulose and cellulose derivatives

Recent advances between 1985 and early 1993 in the following topics of the characterization of molecular structure and molecular properties of cellulose and its derivates (CD) made in the authors' laboratories are briefly reviewed: (1) A theoretical basis of the assignment of carbonyl carbon peaks of ¹³C NMR spectra on cellulose acetate (CA) was given, especially when the total degree of substitution <<f>> is below 3. (2) Molar fractions of 8 kinds of unsubstituted and partially or fully substituted anhydroglucopyranose units were successfully determined for CA and sodium cellulose sulfate (NaCS). (3) The sequence distribution of substituted and unsubstituted anhydroglucopyranose units along a water–soluble CA chain was evaluated. (4) C₆-substituted (i.e., 6-O-acetyl) CA and C₂- and C₆-substituted CA were synthesized, and the full assignment of the ¹³C NMR spetrum of the former was given and a new method for evaluating the degree of substitution at C₆ position was proposed. (5) By destructing the intramolecular hydrogen bonding, cellulose becomes soluble in aq. sodium hydroxide. The specific supermolecular structure of aq. sodium hydroxide, dissolving mechanism, dissolved state and molecular parameters of cellulose in aq. sodium hydroxide were discussed. (6) The solubility behavior of CA with a wide range of total degree of substitution in solvents including water, acetone/water and acetone is controlled by the distribution of substitution and the supermolecular structure. (7) The existence of O₃-H … O'₅ intramolecular hydrogen bonds in a water-in soluble cellulose derivative with hydrophilic substituent (NaCEC) was confirmed by CP/MAS ¹³C NMR and deuteration IR method. At a relatively low degree of substitution the solubility of the derivative in water or aqueous alkali was mainly governed by considerable destruction of the intramolecular hydrogen bonds. (8) The persistence length q, evaluated directly by small-angle X-ray scattering (SAXS) on CA with different total degree of substitution <<f>> ranging from 0,8 to 2,9 confirmed definitely the conclusion drawn before by Kamide and Saito on the molecular rigidity of CD, especially the effect of <<f>> on q. (9) C₆-substituted CA shows different solubility towards dimethylacetamide and water at 20°C, as compared with C₂- and C₃-subsituted CA and C₂-, C₃- and C₆- substituted CA, whose <<f>> is ca. 0,6.     

4-溴-5-甲基靛红的Baeyer-Villiger氧化产物的波谱分析

４－溴－５－甲基靛红分别与单过邻苯二甲酸，过硫酸钾－硫酸两种氧化剂发生Ｂａｅｙｅｒ－Ｖｉｌｉｇｅｒ反应，生成两种同分异构体：５－溴－６－甲基－１Ｈ－苯并［１，３］嗪－２，４－二酮和新化合物５－溴－６－甲基－１Ｈ－苯并［１，４］嗪－２，３－二酮。利用ＭＳ、１３ＣＮＭＲ、１ＨＮＭＲ、ＩＲ对产品结构进行了分析鉴定。     

新型2-取代氨基-3-氟-4-吡啶氟硼酸钾盐的合成

以2,3-二氟-5-氯吡啶为原料,依次经取代和还原反应制得2-取代氨基-3-氟吡啶化合物(2a~2g); 2a~2g与正丁基锂及硼酸三异丙酯经有机锂化法制得相应的硼酸化合物(3a~3g); 3a~3g分别与氟化氢钾经取代反应合成了7个新型的2-取代氨基-3-氟-4-吡啶氟硼酸钾盐,其结构经¹H NMR, ¹³C NMR, IR, ESI-MS和元素分析表征。     

1-苄氧羰基-3-叔丁氧羰酰氨基氮杂环丁烷的合成工艺改进

以苄胺和环氧氯丙烷为原料,经开环、关环、取代、还原、脱苄等反应合成了1-苄氧羰基-3-叔丁氧羰酰氨基氮杂环丁烷,总收率22.9%.其结构经1H NMR,13C NMR和MS表征.     

新型(Z)-2-[(苯氧基)(芳基)]次甲基-2-丁烯酸酯类化合物的合成

以三苯基膦为催化剂,氮气保护下在苯中实现了取代苯酚与α-取代-2,3-丁二烯酸酯的β'-极化加成反应,合成了16个新型(Z)-2-[(苯氧基)(芳基)]次甲基-2-丁烯酸酯类化合物,其结构经1H NMR,13C NMR和MS(ESI)表征。     

Facile synthesis of novel fluorinated thieno[2,3-d]pyrimidine derivatives containing 1,3,4-thiadiazole

A series of novel fluorinated thieno[2,3-d]pyrimidine derivatives incorporating 1,3,4-thiadiazole were synthesized by a facile microwave-assisted procedure,including the cyclization of 2-aminothiophene-3-carbonitrile with trifluoroacetic acid,chlorination and nucleophilic substitution reaction.This protocol offered such advantages as mild reaction conditions,short reaction time, simple puritication and good yields.The structures of the products were characterized by ~1H NMR,MS,elemental analysis and Xray diffraction.     

新型吡啶衍生物的合成

以2-甲基吡啶为原料,经氧化、硝化、还原反应合成了重要中间体4-氨基-2-甲基吡啶(3); 3分别经1,4-加成反应、Heck反应及取代反应合成了11个吡啶类化合物(4~14),其中5, 6和8~14为新化合物,其结构经¹H NMR, ¹³C NMR, MS和HR-MS进行表征。     

Interactions of ionic liquids with polysaccharides 9. Hydroxyalkylation of cellulose without additional inorganic bases

Water-soluble hydroxyalkyl cellulose with a molar degree of substitution of up to 2.79 was prepared under completely homogeneous reaction conditions in various ionic liquids without addition of inorganic bases. In acetate containing solvents the IL acts as a catalyst. The substitution patterns of the cellulose ethers were analyzed by ¹³C NMR spectroscopy, ¹H NMR spectroscopy after peracetylation and GLC/MS after permethylation and depolymerization. A diminished tendency towards the formation of side chains compared to heterogeneously prepared hydroxyalkyl celluloses in the presence of inorganic bases was found.     

Synthesis of O‐(2,3‐dihydroxypropyl) cellulose in NaOH/urea aqueous solution: As a precursor for introducing “necklace‐like” structure

O‐(2,3‐dihydroxypropyl) cellulose (DHPC) samples were synthesized by etherification of cellulose with glycidol (GLY) in a NaOH/urea aqueous solution system under different reaction conditions, so that they had different degrees of ether substitution (DS) in both the overall and regional distributions. The characterization was made by NMR spectroscopy in order to clarify the effects of the molar ratio of in‐fed GLY to anhydroglucose unit and of the reaction temperature not only on the total and regional DSs but also on the molar substitution (MS_dhp) for the multireactive dihydroxypropyl group. The evaluation of MS_dhp was performed after complete propionylation of each DHPC sample. Determination of molecular weights was also conducted on the propionylated DHPCs by GPC analysis. As a preliminary extension, butyralization of DHPC was undertaken in aqueous solution by using p‐toluenesulfonic acid as catalyst together with butyraldehyde (BuA). Two‐dimensional NMR (¹H–¹³C gHSQC) spectra measurements revealed that the products contained butyral groups, owing to dehydration‐cyclization between the BuA‐carbonyl and the duplicate hydroxyls in the side chain of DHPC. Such butyral derivatives of cellulose are expected to be a promising functional material parallel or superior to poly(vinyl butyral) available for safety glass interlayers, etc. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3590–3597     

Synthesis,Structure, and Some Transformations of Novel 1,5‐methanonaphtho[1,2‐g][1,3,5]oxadiazocine Derivatives

Biginelli reaction of thiourea, 2‐hydroxy‐1‐naphthaldehyde, and acetoacetic ester (or benzoyl acetone) under solvent‐free conditions and MW irradiation gave novel 3‐thioxo‐2,3,4,5‐tetrahydro‐1H‐1,5‐methanonaphtho[1,2‐g][1,3,5]oxadiazocine derivatives. Subsequent reaction of the obtained compounds with α‐chloroacetamide led to 5‐methyl‐5H,13H‐5,13‐methanonaphtho[1,2‐g] thiazolo[2,3‐d][1,3,5]oxadiazocin‐1(2H)‐ones, which were converted to the Z‐isomers of 2‐arylylidene‐5H,13H‐5,13‐methanonaphtho[1,2‐g]thiazolo[2,3‐d][1,3,5]oxadiazocin‐1(2H)‐one derivatives by reaction with arylaldehydes. The structures of the products were characterized by 1H NMR, 13C NMR spectra, and X‐ray analysis.     

Synthesis of hyperbranched poly(ether nitrile)s by one‐step polycondensation of an AB2 monomer

Hyperbranched poly(ether nitrile)s were prepared from a novel AB₂ type monomer, 2‐chloro‐4‐(3,5‐dihydroxyphenoxy)benzonitrile, via nucleophilic aromatic substitution. Soluble and low‐viscous hyperbranched polymers with molecular weights upto 233,600 (M_w) were isolated. According to the ¹H NMR and GPC data, the unique polymerization behavior was observed, which implies that the weight average molecular weight increased after the number average molecular weight reached plateau region. Model compounds were prepared to characterize the branching structure. Spectroscopic measurements of the model compounds and the resulting polymers, such as ¹H, DEPT ¹³C NMR, and MS, strongly suggest that the ether exchange reaction and cyclization are involved in the propagation reaction. The side reactions would affect the unique polymerization behavior. The resulting polymers showed a good solubility in organic solvents similar to other hyperbranched aromatic polymers. The hydroxy‐terminated polymer was even soluble in basic water. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5835–5844, 2009     

7-氯-[1，2，3，4]-四氢吩嗪-[2，3]-并富勒烯[60]的合成

60富勒烯及其衍生物因其结构的特殊性,在有机超导、分子磁性、有机发光材料、分子器件、非线性光学活性、能量代谢和生物活性等[1]方面表现出独特的性能和潜在的应用前景,是非常活跃的研究领域之一.     

Ionic‐Liquid‐Derived,Water‐Soluble Ionic Cellulose

A new type of water‐soluble ionic cellulose was obtained by means of the dissolution of cellulose in dimethylimidazolium methylphosphite at elevated temperatures over 120 °C. FTIR spectroscopy, ¹H and ¹³C NMR spectroscopy, and elemental analysis results revealed that the repeating unit of the water‐soluble cellulose consists of a dialkylimidazolium cation and a phosphite anion bonded to cellulose. The degree of phosphorylation on the cellulose chain was between 0.4 and 1.3 depending on the reaction temperature and time. With an increasing degree of phosphorylation, water solubility was increased. Scanning electron microscopy and X‐ray diffraction analyses revealed that the cellulose crystalline phase in the parent crystalline cellulose changed to an amorphous phase upon transformation into ionic cellulose. Thermogravimetric analysis showed the prepared phosphorylated cellulose was stable over 250 °C and a substantial amount of residue remained at 500 °C.     

由三氟异丙烯基溴化镁制备羧酸

以三氟丙烯和溴为原料加成制得1,2-二溴三氟丙烷,脱溴化氢得到2-溴三氟丙烯,再在一定条件下合成2-溴三氟丙烯的格氏试剂（三氟异丙烯基溴化镁）,与CO2反应最终生成1-溴-2-三氟甲基丙酸。 用碳酸钠溶液萃取的方法得到0.8 g产品,纯度为99.6%,收率为3.6%。 对产物进行了MS、IR、1H NMR和13C NMR等表征,并分析了主要副产物1,2-二氟丙二烯和2,3-二三氟甲基-1,3-丁二烯及其与未反应的2-溴三氟丙烯间的[2+2]或[2+4]环加成反应产物。 确定以2-溴三氟丙烯为原料经格氏反应制羧酸较好的反应条件为：以THF为溶剂,1,2-二溴乙烷作引发剂,制备格氏试剂温度为30 ℃,CO2与格氏试剂反应温度为0 ℃。     

Novel cellulose esters derived from the levopimaric acid-maleic anhydride adduct: synthesis,characterization, and properties

Synthesis of maleated pimaric acid (MPA) cellulose esters is first reported in this work. Cellulose esterification was performed by reacting microcrystalline cellulose with monoacid chloride of MPA (MPA-Cl) in presence of pyridine as catalyst and reaction medium. The syntheses were started in a heterogeneous solid–liquid reaction medium, but as the reaction advanced, the reaction mass turned into a homogeneous solution. The effects of MPA-Cl/anhydroglucose unit molar ratio, reaction temperature, and reaction duration on the yield and degree of substitution (DS) of cellulose esters (CEs) were investigated. CEs with DS ranging from 2.6 to 2.8 were achieved at molar ratios of 5.5–6.0 after 12–16 h at 118 °C. The purified products were characterized by elemental analysis, IR and ¹³C-NMR spectroscopy, and thermogravimetric analysis. CEs are soluble or partially soluble in usual organic solvents, depending on DS. Transparent films were prepared using CE-cyclohexanone solutions.     

Synthesis and Spectroscopic Properties of S-,O-Substituted Naphthoquinone Dyes

New S-,O-substituted naphthoquinone compounds (3a, 4b, 6, 7c, 9d, 10, 12, 13c, 14d, 15) were synthesized via vinilic substitution. 2,3-Dichloro-1,4-naphthoquinone gave 3a and 4b with 4,4′-thiobisbenzenethiol, respectively. Compounds 6 and 7c were obtained from the reaction of 2,3-dichloro-1,4-naphthoquinone with cyclohexylmercaptane. The compounds 9d and 10 were prepared from the reaction of 2,3-dichloro-1,4-naphthoquinone with 6-mercapto-1-hexanol. Compounds 12, 13c, 14d, and 15 were synthesized from the reaction of 2,3-dichloro-1,4-naphthoquinone with 1,6-hexanedithiol. Their structures were characterized by micro analysis, FT-IR, ¹H NMR, ¹³C NMR, MS, UV-Vis, and fluorescence spectroscopy.