α-甲氧甲酰基-γ-丁内酯和α-乙氧甲酰基-γ-丁内酯的合成及表征

以γ-丁内酯为原料,分别与碳酸二甲酯、碳酸二乙酯,在氢化钠的催化下,利用α氢的活泼性制得α-甲氧甲酰基-γ-丁内酯和α-乙氧甲酰基-γ-丁内酯。探索了反应温度、反应时间、反应物配比、催化剂用量对产率的影响。结果表明,适宜的反应条件为:①合成α-甲氧甲酰基-γ-丁内酯反应温度25℃,催化剂0.3 mol,反应时间3 h,反应物料物质的量比1∶1.5,产率可达85%;②合成α-乙氧甲酰基-γ-丁内酯反应温度30℃,催化剂0.3 mol,反应时间4 h,反应物物质的量比1∶2,产率可达76%。对产品进行了核磁共振氢谱、红外光谱表征。     

3,5-二氯-2-戊酮的合成研究

以α-氯-α-乙酰基-γ-丁内酯、固体光气为原料,N,N-二甲基哌啶盐酸盐为催化剂合成了3,5-二氯-2-戊酮。考察了催化剂种类、氮气通入速率、物料配比、滴加时间、滴加温度等因素对反应的影响。优化条件下,3,5-二氯-2-戊酮的含量94.0%,收率81.5%(以α-氯-α-乙酰基-γ-丁内酯计)。     

α-乙酰基-γ-丁内酯合成新工艺研究

以γ-丁内酯,乙酸乙酯为原料,金属钠和乙醇钠为催化剂,甲苯为溶剂合成α-乙酰基-γ-丁内酯。在金属钠与乙醇钠的钠摩尔比为7:3,甲苯/γ-丁内酯(w/w)=2.51,反应温度85~90℃,反应时间5h,n(乙酸乙酯):n(GBL):金属钠为2.27:0.9:1的条件下;GBL转化率≥98%,ABL收率≥95%。     

4-氯丁酸甲酯的绿色合成研究

研究了以固体光气代替氯化亚砜和光气对γ丁内酯开环合成4-氯丁酸甲酯绿色工艺,确定了优惠工艺条件为：m（催化剂A）：m（催化剂B）=0．03：0．002,n（丁内酯）：n（固体光气）=2．8：1,保温温度100℃,保温时间24h。在此工艺条件下,4-氯丁酸甲酯的平均收率95．6％。该工艺简单。成本低廉。     

3-环己基丙酸的合成

以丙烯酸甲酯和环己醇为原料,经过酯交换反应合成γ,γ-环戊基丁内酯,γ,γ-环戊基丁内酯加氢得到3-环己基丙酸。考察了2步反应的催化剂和反应条件对产物收率的影响。研究结果表明,酯交换反应的优化条件为:过氧化二叔丁基为引发剂,n(丙烯酸甲酯)∶n(环己醇)=1∶4,反应温度160℃,反应时间6 h;在该条件下,γ,γ-环戊基丁内酯的收率可达93.3%;以0.5%铅/氧化铝为催化剂,γ,γ-环戊基丁内酯加氢反应的优化条件为:反应温度为250℃,γ,γ-环戊基丁内酯空速0.2 h-1,反应压力3.0 MPa,氢气空速500 h-1,在该条件下,γ,γ-环戊基丁内酯转化率78.0%,环己基丙酸选择性80.2%。     

1-苯基-2-吡咯烷酮的合成

以磷酸作催化剂,γ 丁内酯与苯胺反应合成了1 苯基 2 吡咯烷酮,确定了反应的最佳工艺条件:n(γ 丁内酯)∶n(苯胺)∶n(磷酸)=1 0∶1 5∶0 1,反应时间2h,反应温度为180～210℃;产物经减压蒸馏、重结晶分离提纯,过量苯胺经蒸馏、分水后回收,蒸馏后的残余物作催化剂循环使用,1 苯基 2 吡咯烷酮收率为96 2%,质量分数99 5%;产品用元素分析、红外、核磁进行了确证。     

环丙胺合成的新方法

采用γ 丁内酯和异丙醇为起始原料 ,经 5步反应合成环丙胺 :γ 丁内酯开环酯化得γ 氯代丁酸异丙酯 (Ⅰ ) ,产率 93% ;通过固 /液相转移催化 (PTC) ,由Ⅰ合成了环丙烷甲酸异丙酯 (Ⅱ ) ,产率 92 % ;Ⅱ经液 /液PTC水解、中和制得环丙烷甲酸 (Ⅲ ) ,产率 85 % ;Ⅲ和尿素发生酰化反应 ,生成环丙甲酰胺 (Ⅳ ) ,产率 82 9% ;最后Ⅳ经Hofmann降解 ,得目的产物环丙胺 (Ⅴ ) ,产率87 2 % ,总收率达 5 2 6 %。在环化和水解这关键的两步采用了相转移催化 ,使得整个路线反应条件温和 ,时间短 ,原材料价廉易得 ,可望适合工业规模生产。     

γ-丁内酯的生产现状和市场前景

概述了γ 丁内酯的性质及用途 ,介绍了国内外γ 丁内酯的市场需求和生产状况 ,预测了国内市场前景     

在NiO-SiO_2气凝胶催化剂上顺酐液相加氢合成γ-丁内酯

以硝酸镍和正硅酸乙酯为原料 ,采用溶胶 -凝胶超临界流体干燥技术 (Sol-Gel-SCFD)制备了w(Ni) =30 %的NiO -SiO2 气凝胶催化剂。通过TPR、TEM等手段对该催化剂进行了表征并通过正交实验对顺酐液相加氢工艺条件进行了优化选择 ,结果表明 :在气凝胶催化剂中活性组分NiO与载体SiO2 之间存在较强相互作用 ,且二者均为高度分散的纳米粒子。在 180℃ ,6 0MPa压力下反应 8h ,顺酐转化率接近 10 0 %,γ 丁内酯的选择性达 80 16 %。在一定温度范围内升高温度有利于γ 丁内酯的生成。     

4-氯丁酰氯的合成研究

以-γ丁内酯为原料、无水氯化锌作催化剂、氯化亚砜做氯化剂进行开环氯化合成4-氯丁酰氯。对该氯化反应原理进行了阐述,考察了影响反应的主要因素。优化工艺条件为:在55℃加热搅拌反应22h,催化剂用量3%～5%,收率82.7%。     

Simulation and optimization of the thermally coupled reactive distillation column for producing toluene diisocynate

Toluene diisocyanate is an important chemical intermediate prepared by phosgenation reaction with two steps named cold and thermal phosgenation, respectively. The thermal phosgenation reaction is a complex reactive distillation process with high energy consumption and multiple targets of reaction and separation, so it is of great significance to optimize the step. The reactive distillation model of the thermal phosgenation was established for an industrial installation by aspen plus, and the effects of the different parameters of temperatures, residence times, etc., were investigated firstly; then a thermally coupled reactive distillation column was presented to perform the thermal phosgenation process, and the optimal operation and configuration parameters were obtained by simulation. The results showed that the proposed process can save the heat and cold energy with 7.29% and 32.78%, respectively, and reduce the total annual cost by about 17.11%.     

异氰酸正丁酯工艺优化

通过正交实验,研究低温、高温光气化反应的影响因素,通过稳定性实验确定反应的最佳条件。对光气化工艺和精馏方案优化,使得产品纯度达到99.5%以上。     

Conductivities and ion association of 1:1 electrolytes in aprotic solvents

Molar conductivities for several alkali metal salts and tetraalkylammonium salts have been measured at 25°C in 4-butyrolactone and propylene carbonate over the concentration range of 0.01–0.001 mol dm^?3. The data were analysed by Justice's method, and the results compared to corresponding data for acetonitrile solutions. From a consideration of dielectric constants, ion pairing is expected to be similar in 4-butyrolactone and acetonitrile solutions. However we find that ion pair formation in 4-butyrolactone is very similar to that in propylene carbonate. When interpreted in terms of the Bjerrum treatment of ion pair formation, this behaviour can be attributed to the formation of solvent separated ion pairs in 4-butyrolactone whereas in propylene carbonate and acetonitrile, all salts form simple “contact” ion pairs.     

HDI的制备

综述了六亚甲基二异氰酸酯（HDI）的制备方法,主要有光气化法和热分解法。对光气化法若干工艺因素加以讨论。     

Interfacial synthesis and characterization of random and segmented block bisphenol A–tetrabromobisphenol A copolycarbonates

The chain sequence architecture of bisphenol A–tetrabromobisphenol A copolycarbonates depends on the process employed to prepare them. An interfacial process involving a single-step phosgenation produces a segmented block copolymer, contrary to previous assumptions. An interfacial two-step phosgenation process allows the preparation of random copolycarbonates. In each process the control of the pH of the acqueous phase of the two phase reaction mixture is required to achieve complete comonomer conversion to copolymer and to obtain the desired sequence architecture. The chain sequence architecture of these copolycarbonates can be estimated by examination of their Fourier transform infrared spectra. The relative bandwidth of the carbonate stretching band is roughly proportional to the copolycarbonate number average sequence length, allowing the facile distinction between block and random copolymers. The number average sequence lengths of these copolycarbonates were quantified by carbon-13 NMR spectroscopy. These analyses showed that the one-step phosgenation process yields segmented block copolycarbonates having number average sequence lengths from about 4 to 9, and the two-step phosgenation process produces random copolycarbonates having sequence lengths from 1.6 to 2. The distribution of the aromatic carbon triads of these random copolymers shows them to have an alternate-segmented block architecture, which is consistent with the synthesis conditions, rather than a statistically random distribution of comonomer segments. Dynamic mechanical analysis of two of these copolycarbonates shows a dependence of their low temperature secondary transitions on the copolymer sequence structure. A segmented block copolycarbonate, having a number average sequence length of about 4, displays two distinct peaks in its tan δ curve at temperatures corresponding to those transitions observed in the respective homopolymers. The tan δ curve of a random copolycarbonate shows a single low temperature secondary transition midway between those of the homopolymer. © 1994 John Wiley & Sons, Inc.     

多胺光气化制MDI过程中化学问题的探讨

本文研究探讨了多胺光气化制MDI过程中的化学问题,揭示了影响聚合MDI质量,诸如NCO的含量和储存稳定性的化学因素,确立了多胺光气化制MDI过程中影响聚合MDI质量的关键因素及过程。     

α-[[2-甲氧羰基-4-乙酰基苯基]-氧基]-γ-丁内酯的合成

以水杨酸甲酯为起始原料,与乙酰氯酰化后得到5-乙酰水杨酸甲酯,再和α-溴代-γ-丁内酯缩合得到α-[（2-甲氧羰基-4-乙酰基苯基）-氧基]-γ-丁内酯,总收率60.9%。该工艺操作简单,适于工业化生产。     

肉香型香料4-甲基-5-噻唑乙醇的合成

以2-乙酰-γ-丁内酯和二硫代氨基甲酸铵为主要原料,通过氯化、脱羧、环合和氧化反应合成了4-甲基-5-噻唑乙醇。44g氯气在30~35℃时于3~4h内通入到含有71g2-乙酰-γ-丁内酯的碳酸氢钠水溶液,得到3-氯-2-乙酰-γ-丁内酯81g,将它溶于w(HCl)=1%盐酸水溶液中,加热脱羧生成3-氯-5-羟基戊酮50g,接着与60g的二硫代氨基甲酸铵在40℃和pH=2的水溶液中反应,生成2-巯基-4-甲基-5-噻唑乙醇58g,用w(H2O2)=30%的过氧化氢130g氧化,萃取、蒸馏得到4-甲基-5-噻唑乙醇40·3g,质量分数98·8%,总收率50·2%。该合成工艺已经在50t/a的生产装置上中试放大,总收率为46·7%。     

The interfacial polycarbonate reactions. I. Defining the critical process parameters

Polycarbonate is prepared by the interfacial phosgenation and polycondensation of bisphenol A (BPA) in methylene chloride with caustic using triethylamine as a catalyst. In a typical batch reactor, where phosgenation and oligomerization proceed simultaneously, the critical process parameters are intermingled and are difficult to determine. Therefore, a semicontinuous process consisting of a series of static mixers for continuous phosgenation, followed by a batch reactor for oligomerization and polycondensation, was developed for better understanding of the reaction mechanisms. Phosgene hydrolysis was reduced greatly going from a batch to a continuous reactor (excess phosgene was reduced from 30 to 5%). Variables which influence the composition of intermediates are linear velocity, organic to aqueous volume ratio, PH (BPA to NaOH ratio), and phosgene to BPA ratio. These variables also affect BPA conversion, amount of phosgene hydrolysis, terminator capping efficiency, molecular weight, and molecular weight distribution of the resulted polycarbonate. Oligomerization takes place at the interface, and monochloroformates (HO-B_n-OCOCI) which contain both hydrophilic and lipophilic end groups, stay at the interface and, hence, react preferentially. Oligomers are analyzed by a newly developed HPLC technique.