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在三乙醇胺介质中,新试剂1-(2-羟基-3,5-二硝基苯基)-3-[4-(苯基偶氮)苯基]-三氮烯(HDNPAPT)与季铵盐型阳离子表面活性剂及阴离子表面活性剂(AS)反应显色,形成三元络合物.研究了显色体系的条件实验,建立了测定阴离子表面活性剂十二烷基苯磺酸钠(DBOSO_3Na)、十二烷基磺酸钠(DOSO_3Na)和十二烷基硫酸钠(DSO_4Na)的方法,表观摩尔吸光系数均达10~4以上.方法已应用于环境水样中阴离子表面活性剂的测定. 相似文献
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1-(3-硝基苯基)-3-[4-(苯基偶氮)苯基]-三氮烯与阳离子表面活性剂显色反应的研究及应用 总被引:4,自引:0,他引:4
在NaOH碱性介质中,1 (3 硝基苯基) 3 [4 (苯基偶氮)苯基] 三氮烯(m NPPAPT)分别与阳离子表面活性剂(CS)溴化十六烷基三甲铵(CTMAB)、溴化十二烷基二甲基苄铵(DDMBAB)、溴化十六烷基吡啶(CPB)和溴化十四烷基吡啶(TPB)反应显色形成离子配合物,它们与m NPPAPT形成离子配合物比均为2∶1。CTMAB、CPB、TPB、DDMBAB与m NPPAPT形成配合物最大吸收波长分别位于538、538、625、637nm,表观摩尔吸光系数达(103~104)L·mol-1·cm-1。研究了测定微量阳离子表面活性剂的条件,建立了新的分析方法,并应用于实样分析。 相似文献
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SPAPT-CTMAB-AS显色反应的研究及应用 总被引:2,自引:0,他引:2
合成的新试剂1-(4-磺酸基苯基)-3-[4-(苯基偶氮)苯基]-三氮烯(SPAPT)与阳离子表面活性剂溴化十六烷基三甲铵(CTMAB)和阴离子表面活性剂(AS)在三乙醇胺调节的碱性(pH
11.00~11.20)介质中形成三元显色配合物。配合物最大吸收λ位于590 nm,测定阴离子表面活性剂十二烷基苯磺酸钠(DBOSO 相似文献
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由于在1-吡啶-3-[4-(苯基偶氮)苯基]-三氮烯(PYPAPT)的分析功能基(N=N-NH)上引入了强助色杂环吡啶基,当PYPAPT与阳离子表面活性剂溴化十六烷基三甲铵(CTMAB)、溴化十六烷基吡啶(CPB)显色时,表现出它是高灵敏的显色试剂。本文研究结果与文献报道1-(4-硝基苯基)-3-[4-(苯基偶氮)苯基]-三氮烯、1-(2-羟基-3,5-二硝基苯基)-3.[4-(苯基偶氮)苯基]-三氮烯、1-(5-萘酚-7-磺酸)-3-[4-(苯基偶氮)苯基]-三氮烯(NAS-APAPT)及1-(2-6-二氯-4-硝基苯)-3-(4-硝基苯)-三氮烯与阳离子表面活性剂显色反应比较,PY 相似文献
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新试剂1-(2-羟基-3,5-二硝基苯基)-3-[4-(苯基偶氮)苯基]-三氮烯的合成及与季铵盐型阳离子表面活性剂的显色反应 总被引:8,自引:0,他引:8
合成了新试剂1-(2-羟基-3,5-二硝基苯基)-3-[4(苯基偶氮)苯基]-三氮烯(HDNPAPT),研究了该试剂在NaOH介质中与阳离子表面活性剂漠化十六烷基三甲铵(CTMAB)、溴化十六烷基吡啶(CPB)、溴化十二烷基二苄铰(DDMBAB)形成1:3的紫红色离子缔合物显色体系.测定了显色体系表面活性剂的临界胶束浓度、表观摩尔吸光系数ε_(max)、符合比尔定律的范围.探讨了微量阳离子表面活性剂CMTAB、CPB和DDMBAB的测定方法,结果满意. 相似文献
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1-(5-萘酚-7-磺酸)-3-[4-(苯基偶氮)苯基]-三氮烯-溴化十六烷基吡啶-阴离子表面活性剂显色反应研究 总被引:6,自引:0,他引:6
合成了新试剂1 (5 萘酚 7 磺酸) 3 [4 (苯基偶氮)苯基] 三氮烯(NASA PAPT)。研究了在三乙醇铵介质中,阳离子表面活性剂溴化十六烷基吡啶(CPB)存在下,NASAPAPT与阴离子表面活性剂(AS)的显色反应。NASAPAPT与AS形成1∶3的紫红色络合物,络合物最大吸收位于588nm,表观摩尔吸光系数为1.06×104~1.14×104L·mol-1·cm-1。研究检测AS的新方法应用于废水分析,测定结果与经典分析结果吻合。 相似文献
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1-吡啶-3-[4-(苯基偶氮)苯基]-三氮烯-溴化十六烷基吡啶-阴离子表面活性剂显色反应的研究及应用 总被引:4,自引:0,他引:4
在氢氧化钠 氯化钠 甘氨酸 (NaOH NaCl CH2 (NH2 )COOH)缓冲溶液中 ,1 吡啶 3 [4 (苯基偶氮 )苯基 ] 三氮烯 (PYPAPT)与十二烷基苯磺酸钠等阴离子表面活性剂 (AS)和溴化十六烷基吡啶 (CPB)阳离子表面活性剂形成三元紫蓝色配合物 ,配合物在 6 3 0nm处有最大吸收。利用此显色反应分别测得十二烷基苯磺酸钠、十二烷基磺酸钠、十二烷基硫酸钠阴离子表面活性剂 (AS)的表观摩尔吸光系数ε630 分别为 1 6 1× 1 0 4 、1 .44× 1 0 4 和 1 .76× 1 0 4 L·mol- 1 ·cm- 1 。方法已应用于合成水样及环境水样中阴离子表面活性剂的测定。 相似文献
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以高藜芦胺为起始原料,经N-磺酰化反应制得高藜芦磺酰胺(2);2分别与芳乙烯甲醚经对甲苯磺酸催化的Pictet-Spengler反应后用金属钠脱除Ts基团合成了(±)-norlaudanosine(5a)和(±)-O,O-dimethylcoclaurine(5b);使用半量拆分法,以N-乙酰-L-苯丙氨酸为拆分剂,制得(S)-(-)-5a和(S)-(-)-5b,其结构经1H NMR,13C NMR,IR,MS和HR-ESI-MS确证。 相似文献
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Shin-ichi Takekuma Keisuke Nagata Yûsuke Yoshioka Hironori Obata Takaharu Minami Tomoyoshi Tanaka Keisuke Yashima Toshie Minematsu Hideko Takekuma 《Tetrahedron》2012,68(33):6737-6758
Wittig reactions of 2-furaldehyde (20) [and thiophene-2-carbaldehyde (21)] with (3-guaiazulenylmethyl)triphenylphosphonium bromide (19) in ethanol containing NaOEt at 25 °C for 24 h under argon give (E)-1-(2-furyl)-2-(3-guaiazulenyl)ethylene (22E) and (E)-1-(2-thienyl)-2-(3-guaiazulenyl)ethylene (23E) in 53 and 36% yields. Similarly, Wittig reactions of 3-furaldehyde (29) [and thiophene-3-carbaldehyde (30)] with 19 under the same reaction conditions as for 20 and 21 afford (E)-1-(3-furyl)-2-(3-guaiazulenyl)ethylene (31E) and (E)-1-(3-thienyl)-2-(3-guaiazulenyl)ethylene (32E) in 32 and 46% yields. Molecular structures and characteristic properties as well as preparation of the title E (i.e., one of the geometrical isomers) forms, with a view to comparative study, are reported. Moreover, reactions of those conjugated π-electron systems with TCNE (=tetracyanoethylene) in benzene [and in DMF (=N,N-dimethylformamide)] at 25 °C for 24 h under argon yield unique products, possessing interesting molecular structures, respectively, whose characteristic properties and crystal structures are documented, also. 相似文献
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Enantioselective synthesis of (R)-Rolipram 1 has been achieved through a conjugate addition of cyanide to enantiomerically pure 2-(2-aryl ethenyl)oxazoline 2, followed by selective reduction of the adduct with NaBH4-NiCl2. 相似文献
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SG Davies JA Lee PM Roberts JP Stonehouse JE Thomson 《The Journal of organic chemistry》2012,77(16):7028-7045
The highly diastereoselective conjugate additions of the novel lithium amide reagents lithium (R)-N-(3-chloropropyl)-N-(α-methylbenzyl)amide and lithium (R)-N-(3-chloropropyl)-N-(α-methyl-p-methoxybenzyl)amide to α,β-unsaturated esters were used as the key steps in syntheses of the homalium alkaloids (-)-(S,S)-homaline and (-)-(R,R)-hopromine. The asymmetric synthesis of (-)-(S,S)-homaline was achieved in 8 steps and 18% overall yield, and the asymmetric synthesis of (-)-(R,R)-hopromine was achieved in 9 steps and 23% overall yield, from commercially available starting materials in each case. These syntheses therefore represent by far the most efficient total asymmetric syntheses of these alkaloids reported to date. A sample of the (4'R,4'S)-epimer of hopromine was also produced using this approach, which provided the first unambiguous confirmation of its absolute configuration and therefore that of natural (-)-(R,R)-hopromine. 相似文献
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1INTRODUCTIONTheSchiffbasesderivedfromb-diketonesandaliphaticamineshavebeenshowntoexistastheketo-amines.However,ifsubstituentseitherattheketooraminogrouparearomatic,itmaybeexpectedtheenoliminewillbethefavoredtautomericform[1].Recently,someSchiffbasesderivedfromTTA(4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione)andPMBPhavebeenstudiedbyWang[2]andYu[3]etal.Inordertostudytherelationshipbetweenthestructuresandperformancesofthesecompounds,thetitlecom-poundwillbereportedherein.2EXPERIMENT… 相似文献
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An efficient synthetic method for the preparation of (E)- and (Z)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles has been developed. The reaction of (E)- and (Z)-3-styrylchromones with hydrazine hydrate afforded the corresponding (E)- and (Z)-4-styrylpyrazoles, respectively, saved 4′-nitro-derivatives where both (E)- and (Z)-4′-nitro-3-styrylchromones afforded (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles. The reaction mechanism for these transformations was discussed and the stereochemistry of all products was assigned by NMR experiments. 相似文献
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《Tetrahedron: Asymmetry》1999,10(22):4393-4403
Three short syntheses of the title compound, a peptidomimetic for the Glu-Glu-Ile-NH2 portion of Ac-pTyr-Glu-Glu-Ile-NH2, a high affinity peptide for the Src SH2 domain, are described. The most efficient route produces the title compound in a final enantiopurity of 94% ee. 相似文献
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