光活性N-苄基-α-苯乙胺的合成

以光活性α-苯乙胺起始原料,以水为溶剂采用烷基化反应合成了光活性N-苄基-α-苯乙胺.产品R-( )-N-苄基-α-苯乙胺的比旋光度[a]D20= 41.3°;S-(-)-N-苄基-α-苯乙胺的比旋光度为[a]D20=-40.6°,收率约75%.     

α-苯乙胺的合成及拆分

文章综述了外消旋α-苯乙胺由苯乙酮,苯甲腈,苯甲胺的合成,进一步介绍了光学活性α-苯乙胺由肟醚苯甲醛苯乙酮苯甲腈的不对称合成,以及由拆分方法制备光学活性α-苯乙胺,如用手性酰化试剂选择性与苯乙胺形成酰胺的动力学拆分,通过选择性生成结晶盐拆分。笔者用组合方法拆分α-苯乙胺并加入不同添加剂得出不同的结果。最后得出结论,寻找合适的添加剂是有效拆分的一条有希望的途径。     

α-苯乙胺的拆分

本文叙述了一种α-苯乙胺的拆分方法,采用磷霉素的对映体、具有光学活性、但无抗菌活力的(+)顺1、2环氧丙基磷酸为拆分剂,得到(+)α-苯乙胺17.7～18.9g(按投入a-苯乙胺计算,其拆分收率:73.78～81.93%)。B、P 80～100℃/25～30 mmHg。[α]_D~(25)+32.17—34.36 (-)α-苯乙胺14.56g(按投入α-苯乙胺计算,其拆分收率:74.55%)。B、P 80～100℃/25～30 mmHg [α]_D~(25)—36.76     

D-酒石酸拆分外消旋α-苯乙胺工艺研究

以D-酒石酸为拆分试剂,采用程序降温结晶法,对外消旋α-苯乙胺的拆分工艺进行了探究。通过对结晶的工艺、溶剂、温度等条件的优化试验,确定了外消旋α-苯乙胺的最佳拆分工艺,其中(R)-(+)-α-苯乙铵.D-酒石酸盐晶体收率高达95.0%,水解、精馏得(R)-(+)-α-苯乙胺,收率86.5%,ee值为93.0%,[α]2D0+38.3°。同时,开发了一种在四氢呋喃溶液中硫酸酸化D-酒石酸钠回收D-酒石酸的新方法,D-酒石酸的回收率93.0%。其拆分工艺简单,生产成本低,具有良好的工业应用价值。     

旋光性N—苄基—1—苯乙胺

N-苄基-1-苯乙胺(BPA)与1-苯乙胺(PEA)一样均属于非天然类旋光性胺,近年来,其作为碱式光学离析剂的开发工作正在进行之中。BPA的CAS索引号为38235-77-7(R体)、17480-69-2(S体),一般物性见表1,结构式如下:     

消旋正丁基苯酞拆分方法的改进

对消旋正丁基苯酞的化学拆分方法进行了改进,提高了终产物的光学纯度和总收率。方法如下:先将消旋正丁基苯酞在氢氧化钠水溶液中开环、酸化,再与拆分试剂——左旋α-苯乙胺反应得到2个非对映异构体胺盐的混合物,然后用丙酮和左旋α-苯乙胺的混合溶液重结晶,得到左旋正丁基苯酞的左旋α-苯乙胺盐,酸性条件下将其解离并环合,减压蒸馏得到左旋正丁基苯酞,并通过对比实验确定了最优化的工艺条件。改进后的拆分方法有效抑制了左旋正丁基苯酞的左旋α-苯乙胺盐在重结晶过程中的热分解,提高了产物左旋正丁基苯酞的光学纯度(99%ee)和总收率(25%)。     

α-苯乙胺拆分研究

本文采用不溶于水的L-谷氨酸作为拆分剂,在混合溶剂中对消旋α-苯乙胺进行拆分,拆分剂L-谷氨酸可以直接酸化高收率的回收.较好的反应条件是:拆分剂的用量1.05 mol,甲苯用量190 g,稀硫酸浓度15％.S-(-)-α-苯乙胺收率89％,比旋光度:-39.4°;回收混合a-苯乙胺收率92.5％;回收拆分剂收率95.9...     

(1S,5R,6R,7R)-6-羟甲基-7-羟基-2-氧杂双环[3.3.0]辛-3-酮的合成

(1S,5R,6R,7R)-6-羟甲基-7-羟基-2-氧杂双环[3.3.0]辛-3-酮(Ⅵ)是制备前列腺素的关键中间体。为了简化工艺条件,降低生产成本,以环戊二烯和二氯乙酰氯为原料,经环加成、还原和Baeyer-Villiger氧化3步反应制得2-氧杂双环[3.3.0]辛-6-烯-3-酮(Ⅳ),收率83.9%;经光学拆分后,与多聚甲醛经区域选择性Prins反应、粗产品不经分离,直接水解合成了Ⅵ,总收率22.0%。讨论了拆分剂、结晶溶剂对拆分Ⅳ的作用,确定了以R-(+)-苯乙胺为拆分剂,乙酸乙酯为结晶溶剂来拆分Ⅳ,拆分收率34.3%,[α]D20=-104.0°(c=1.0,MeOH),熔点:42~46℃。对Prins反应后水解产物的后处理工艺进行了优化,用氯仿重结晶代替柱分离来精制产品,收率76.5%,[α]D20=-45.0°(c=1.0,MeOH),熔点:117~119℃。目标产物用IR、MS、1HNMR进行了表征。     

光学活性的2-苄基-3-羟基丙酸合成

以丙二酸二乙酯为起始原料,经过苄基化、还原、乙酰化保护、氧化、水解等5个步骤,合成了标题化合物.以水为溶剂,对标题化合物与手性1-苯乙胺形成的非对映异构体盐进行手性拆分,得到了(R)-2-苄基-3-羟基丙酸和(S)-2-苄基-3-羟基丙酸.     

1-(2-羟基-5-甲基苯基)苯乙胺的合成

对甲基苯酚与苯乙酰氯酯化得到苯乙酸 ( 4 -甲基 )苯酯 ;然后在三氯化铝作用下重排得到苄基 ( 2 -羟基 -5 -甲基 )苯基酮 ;此酮经硫酸二甲酯甲基化得到苄基 ( 2 -甲氧基 -5 -甲基 )苯基酮 ,再和甲酸铵反应得到 1-( 2 -甲氧基 -5 -甲基苯基 )苯乙胺 ,最后经氢溴酸水解得到 1-( 2 -羟基 -5 -甲基苯基 )苯乙胺。所有中间体和最终产品的结构均由IR、元素分析、1 HNMR得到证实。     

(S)-1-(1-苯基乙基)-4-哌啶酮的合成

该文以(S)-1-苯乙胺、丙烯酸甲酯为原料,经Michael加成,Dieckmann环合,脱羧,合成了(S)-1-(1-苯基乙基)-4-哌啶酮。并对所涉及的Michael加成反应的工艺参数进行了优化。当(S)-1-苯乙胺与丙烯酸甲酯的摩尔比为1∶2.5,40℃反应10h,收率为92.4%,总收率为89.3%。目标产物及中间体的结构经核磁共振波谱进行了表征。     

1-甲基-3-苯基哌嗪的合成

研究了1 甲基 3 苯基哌嗪的合成工艺。以N 甲基乙醇胺和环氧苯乙烷为起始原料,在80℃下反应4h,得到N (2 羟乙基) N 甲基 α 羟基 β 苯乙基胺,在0～10℃下将其滴加入氯化亚砜,并在45℃下反应2h,生成N (2 氯乙基) N 甲基 α 氯 β 苯乙基胺,通入过量HCl,得其盐酸盐,在40～45℃下再加入氨水反应3h,经减压蒸馏,重结晶得到目标化合物1 甲基 3 苯基哌嗪,总收率43 9%。目标化合物结构经核磁共振分析验证。     

三氟氯菊酸的手性拆分

通过R（+）-α-苯乙胺与三氟氯菊酸在不同反应溶剂中反应,实现了对三氟氯菊酸的手性拆分。研究结果表明,当甲醇作反应溶剂时,R（+）-α-苯乙胺会与三氟氯菊酸络合形成包结物。所得晶体经FT-IR、¹H NMR以及X射线单晶衍射等测试分析手段表征,得出结论：与R（+）-α-苯乙胺形成包结物的三氟氯菊酸立体异构体为Z-（1S,S）-顺式-2,2-二甲基-3-（2-氯-3,3,3-三氟-1-丙烯基）环丙烷羧酸。     

Synthesis and conformational properties of poly(N4-1-phenylethyl-L-asparagines)

Poly(N⁴-1-phenylethyl-L -asparagines) ( 1a, 1b , and 1c ) containing DL-, (R)-, and (S)- side group chirality were prepared by aminolysis of poly(β-methyl-L -aspartate) (PMLA) with DL-, (R)- (+)-, and (S)- (?)-1-phenylethylamine, respectively. The PMLA was synthesized by ring-opening polymerization of β-methyl-L -aspartate-N-carboxy anhydride (NCA) using triethylamine as initiator. The conformations of these polypeptides in the film state were investigated by IR and circular dichroic spectra. The PMLA, 1a , and 1b exist mainly in β-sheet conformation, while 1c forms α-helix that is induced by the (S)-chirality of the side groups. © 1993 John Wiley & Sons, Inc.     

Search for Structural Basis of Interactions of Biogenic Amines with Human TAAR1 and TAAR6 Receptors

The identification and characterization of ligand-receptor binding sites are important for drug development. Trace amine-associated receptors (TAARs, members of the class A GPCR family) can interact with different biogenic amines and their metabolites, but the structural basis for their recognition by the TAARs is not well understood. In this work, we have revealed for the first time a group of conserved motifs (fingerprints) characterizing TAARs and studied the docking of aromatic (β-phenylethylamine, tyramine) and aliphatic (putrescine and cadaverine) ligands, including gamma-aminobutyric acid, with human TAAR1 and TAAR6 receptors. We have identified orthosteric binding sites for TAAR1 (Asp68, Asp102, Asp284) and TAAR6 (Asp78, Asp112, Asp202). By analyzing the binding results of 7500 structures, we determined that putrescine and cadaverine bind to TAAR1 at one site, Asp68 + Asp102, and to TAAR6 at two sites, Asp78 + Asp112 and Asp112 + Asp202. Tyramine binds to TAAR6 at the same two sites as putrescine and cadaverine and does not bind to TAAR1 at the selected Asp residues. β-Phenylethylamine and gamma-aminobutyric acid do not bind to the TAAR1 and TAAR6 receptors at the selected Asp residues. The search for ligands targeting allosteric and orthosteric sites of TAARs has excellent pharmaceutical potential.     

4-(1-苯乙基氨基)-6-硝基喹唑啉的简便合成方法

4—氯—6—硝基喹唑啉与α—甲基苄胺在异丙醇等6种溶剂中，经回流可生成4—(1—苯乙基氨基)—6—硝基喹唑啉，反应可在1．5～2h内完成。通过对产物进行柱层析分离，纯品产率为85．7％，并对产物进行了波谱表征。     

Glow-discharge-induced graft polymerization of acrylic acid onto poly[1-(trimethylsilyl)-1-propyne] film

Graft polymerization of acrylic acid onto poly[1-(trimethylsilyl)-1-propyne] [poly(TMSP)] film was examined. The water contact angle of poly(TMSP) film decreased remarkably from 90 to 15° by plasma treatment, which gradually increased up to 40° after several days. When the film exposed to a glow discharge was heated in an aqueous solution of acrylic acid at 80°C for 24 h, graft polymerization proceeded on the film surface, which was confirmed by ATR-IR and ESCA spectra. Graft polymerization effectively occurred above a threshold temperature (80°C). The water contact angle of the grafted film was about 30°, and did not change with time. In contrast, when a poly(TMSP) film exposed to UV irradiation was heated in an aqueous solution of acrylic acid, graft polymerization took place not only on the film surface but also inside the film.     

Activity of drimane antifeedants and related compounds against aphids,and comparative biological effects and chemical reactivity of (−)- and (+)-polygodial

A series of natural drimanes and related synthetic compounds was tested for antifeedant activity against aphids. Polygodial and warburganal were the most active. The synthetic compounds methyl 9-hydroxydrimenoate and 9-hydroxydrimenal, although active against lepidopteran larvae, were inactive against aphids. Natural (–)-polygodial and the synthetic (+) isomer showed similar levels of activity as aphid antifeedants and in phytotoxicity, fish toxicity, and human taste tests, but reacted at different rates with enantiomers of 1-phenylethylamine.     

Removal of 3—(3,4—dichlorophenyl)—1, 1 dimethylurea from aqueous solution by natural and activated bentonite

The adsorption of 3-(3,4-dichlorophenyl)-1,1 dimethylurea (diuron) on bentonite desiccated at 110°C untreated, and acid treated with H₂SO₄ solutions over a concentration range between 0.25 M and 5.00 M, from aqueous solution at 30°C has been studied. In addition, adsorption of diuron on combined acid/heat treated samples (0.50 M and 2.50 M H₂SO₄/200°C and 400°C) has also been studied. The experimental data points have been fitted to the Freundlich equation in order to calculate the adsorption capacities (K) of the samples; K values range from 0.92 μg g^?1 for the untreated bentonite up to 974.42 μg g^?1 for the 0.50 M H₂SO₄/400°C acid/heat treated bentonite. The removal efficiency (R) has also been calculated; R values ranging from 2.02% for the untreated bentonite up to 97.17% for the 0.50 M H₂SO₄/400°C acid/heat treated bentonite. The adsorption experiments show that bentonite heat treatment is more effective than bentonite acid treatment in relation to adsorption of diuron.