光学活性2-羟基-3-苯基-4-苯甲酰基-N-甲基-γ-内酰胺的制备研究

目的制备有光学活性的2-羟基-3-苯基-4-苯甲酰基-N-甲基-γ-内酰胺.方法利用2-羟基-3-苯基-4-苯甲酰基-N-甲基-y-内酰胺结构上的2位羟基与(-)-(艹孟)氧基乙酸成酯,得两个非对映异构体混合物(3)和(4),经分离后分别水解的方法来拆分其外消旋体.结果得到光学活性的(-)和( )-2-羟基-3-苯基-4-苯甲酰基-N-甲基-γ-内酰胺,总收率分别为30.75%和28.33%,以外消旋体(5)计.结论该拆分方法操作简单,形成的非对映异构体容易通过重结晶及色谱方法进行分离.     

光学活性2-羟基-3-苯基-4-苯甲酰基-N-甲基-γ-内酰胺的制备研究

目的　制备有光学活性的2 羟基-3-苯基-4-苯甲酰基-N-甲基-γ-内酰胺。方法　利用2-羟基-3-苯基-4-苯甲酰基-N-甲基-γ-内酰胺结构上的2位羟基与(-) 艹孟氧基乙酸成酯,得两个非对映异构体混合物(3)和(4),经分离后分别水解的方法来拆分其外消旋体。结果　得到光学活性的( )和(+)-2羟基-3-苯基-4-苯甲酰基-N-甲基-γ-内酰胺,总收率分别为30. 75%和28.33%,以外消旋体(5)计。结论　该拆分方法操作简单,形成的非对映异构体容易通过重结晶及色谱方法进行分离。     

手性药物拆分技术研究进展

对外消旋体进行拆分是获得手性药物的重要方法.综述了手性拆分方法及其分类,分别为结晶拆分法,包括直接结晶法、形成非对映体的结晶法、组合拆分法等;复合和包合拆分法,包括包结拆分法;色谱拆分法等,并结合一些药物对新近发展起来的手性药物拆分技术做了介绍.     

局部麻醉药罗哌卡因的合成工艺研究

目的 优化罗哌卡因的合成工艺.方法 以外消旋体2-哌啶甲酸为起始原料,经手性拆分、酰氯化、酰胺化和N-丙基化得到目标产物罗哌卡因.结果 与结论 目标产物罗哌卡因结构经核磁共振谱进行确证,总收率为25.6％(以外消旋体2-哌啶甲酸计),纯度为98％(HPLC法),光学纯度为99.7％.该路线步骤简短、操作简便、收率高、反...     

手性拆分剂及其手性药物色谱拆分技术的应用进展

近三十年上市的新药中,手性药物占有很大比例,手性药物拆分技术应用广泛,发展也日趋完善.手性拆分(Chiral Resolution)也称作光学拆分(Optical Resolution),亦或称作外消旋体拆分,为立体化学上,用以分离外消旋化合物成为两个不同的镜像异构物的方法[1].例如反应停事件中:药物沙利度胺(反应停)是以对映体的混合物用作缓解妊娠反应药物,造成许多服用过此药的孕妇产下畸婴,经研究发现(R)-沙利度胺具有镇静和缓解妊娠反应作用,而(S)-沙利度胺可酶促水解成邻苯二甲酰谷氨酸并渗透到胎盘,干扰叶酸的合成,产生强致畸作用.     

十二酰基-β-环糊精聚砜共混膜的制备及其在色氨酸手性拆分中的应用

本研究以十二酰基-β-环糊精为手性选择剂,采用浸入沉淀相转化法制备十二酰基-β-环糊精聚砜共混膜,对膜的稳定性和性能进行考察,并将其用于色氨酸外消旋体的手性拆分。同时建立能够拆分色氨酸外消旋体的手性配体交换液相色谱法,并进行方法学考察,用于评价共混膜的手性拆分能力。采用BaseLine C18柱(4.6 mm×250 mm,5μm),流动相为水相(0.375 mmol/L L-苯丙氨酸和0.075 mmol/L硫酸铜溶液,冰醋酸调至pH 4.3)∶甲醇(80∶20),检测波长为278 nm,柱温为35℃,流速为1 ml/min。建立的方法为手性拆分色氨酸对映体提供了参考。     

2,2-二甲基环丙甲酰胺的HPLC测定及其在手性拆分反应监测中的应用

目的 建立2,2-二甲基环丙甲酰胺的HPLC检测方法,并以该非手性的HPLC方法监测2,2-二甲基环丙甲酰胺的手性拆分反应.方法 采用C_(18)反相色谱柱,柱温为40℃,以50mmol/L,pH3.0的磷酸二氢钠:甲醇=1:1(V/V)为流动相,流速为0.5mL/min,检测波长为210nm.结果 2,2-二甲基环丙甲酰胺在10-1000μg/mL浓度范围内线性关系良好,2,2-二甲基环丙甲酰胺、2,2-二甲基环丙甲酸的分离度为14.28;以本法监控酰胺酶的手性拆分反应液,当HPLC测定结果显示反应液中底物不再降低时,手性气相检测表明(S)-2,2-二甲基环丙甲酰胺的ee值达到99.926%.结论 HPLC方法灵敏度高、线性关系良好;HPLC测定结果可以很好地用于2,2-二甲基环丙甲酰胺手性拆分反应的监测.     

1-氨基-2-丙醇的拆分

(2S,3S)-(-)-酒石酸于水中拆分消旋1-氨基-2-丙醇,然后用强酸性阳离子树脂分离,得到核苷类药物合成中间体(R)-(-)-1-氨基-2-丙醇,收率66.6%,拆分剂可直接回收利用.     

L-(-)-肉碱的合成

以自制手性salen-Co^Ⅲ为催化剂，水解动力学拆分外消旋环氧氯丙烷，得到高光学纯度的（S）-（＋）-环氧氯丙烷，再经季胺化、氰化、水解及离子交换制得L-（-）-肉碱，总收率70％[以（S）-（＋）-环氧氯丙烷计]。     

改进(R)-N-乙酰四氢噻唑-2-硫酮-4-羧酸的纯化方法并拆分D,L-对羟基苯甘氨酸

目的 改进新型手性拆分试剂(R)-N-乙酰四氢噻唑-2-硫酮-4-羧酸[(R)-N-Ac-TTCA]的纯化方法,拆分外消旋氨基酸.方法 使用重结晶法提纯(R)-N-Ac-TTCA,在三乙胺存在下,用其拆分外消旋对羟基苯甘氨酸.结果 (R)-N-Ac-TTCA的产率提高了20.5%,比旋光度为-65.2(c 0.20,EtOH),比原来提高8.4%.应用其拆分D,L-对羟基苯甘氨酸得到D-对羟基苯甘氨酸的同时也得到了L-对羟基苯甘氨酸.结论 重结晶的方法简便有效,用(R)-N-Ac-TTCA拆分D,L-对羟基苯甘氨酸可行.     

Structure-activity studies on the activity of a series of cyclopentane GABA analogues on GABAA receptors and GABA uptake

A series of analogues of gamma-aminobutyric acid (GABA) has been investigated for GABA mimetic activity on the isolated guinea-pig ileum, facilitation of [3H]diazepam binding in rat brain membranes and inhibition of [3H]GABA uptake from rat brain cortical slices. The derivatives tested include six racemic amino acids, all of which contain a 'GABA backbone' with the conformation restricted by a cyclopentane or cyclopentene ring system. From the more potent analogues, five optically pure compounds, including (+)-(4S)-4-aminocyclopent-1-ene-1-carboxylic acid and its (-)-4R enantiomer, have also been assessed as GABA agonists. Of the racemic analogues, 4-aminocyclopent-1-ene-1-carboxylic acid and trans-3-aminocyclopentane-1-carboxylic acid were the most potent at GABAA receptors, while most of the analogues had considerable activity on GABA uptake. The individual resolved isomers of 4-aminocyclopent-1-ene-carboxylic acid and of trans-3-aminocyclopentane-1-carboxylic acid displayed great specificity for GABA receptor and GABA uptake sites. For example (+)-(4S)-4-aminocyclopent-1-ene-1-carboxylic acid was approximately twice as potent as GABA and about 600 times more active than the (-)-4R isomer on the guinea-pig ileum, while it was not significantly active as a GABA uptake inhibitor at 500 microM. On the other hand, its (-)-4R isomer was selective for inhibiting GABA uptake with an IC50 equal to that of racemic nipecotic acid.     

盐酸头孢吡肟的合成

以7-ACA为起始原料,经六甲基二硅胺烷保护羧基和氨基、三甲基碘硅烷进行取代后与N-甲基吡咯烷反应以及脱保护制得(6R,7R)-7-氨基-3-[(1-甲基-1-吡咯烷)甲基]头孢-3-烯-4-羧酸盐酸盐,再以丙酮为溶剂与苯并噻唑硫醇活性酯(MAEM)缩合制得盐酸头孢吡肟,总收率59.4%.     

The comparative stability of different types of penicillin and cephalosporin N-pyrryl derivatives

The kinetics of the decomposition of potassium salts of 4-thia-1-azabicyclo[3.2.0.]heptane-3,3-dimethyl-6-amino-7-oxo-N- [2(1H-pyrrolyl)acetyl] -2-carboxylic acid (6R, trans), 4-thia-1-azabicyclo[3.2.0]heptane-3,3-dimethyl-6-amino-7-oxo-N-[2-phenyl - 2(1H-pyrrolyl)acetyl]-2-carboxylic acid (6R, trans), 5-thia-1-azabicyclo[4.2.0.]oct-2-ene-3- [(acetyloxy)methyl]-7-amino-8-oxo-N-[2(1H-pyrrolyl)acetyl]-2-ca rbo xylic acid (6R, trans), 5-thia-1-azabicyclo[4.2.0.]oct-2-ene-3- [(acetyloxy)methyl]-7-amino-8-oxo-N-[2-phenyl-2(1H-pyrrolyl)acetyl ]- 2-carboxylic acid (6R, trans), 5-thia-1-azabicyclo[4.2.0.]oct-2-ene-7-amino-3-methyl-8-oxo-N- [2(1H-pyrrolyl)-acetyl]-2-carboxylic acid (6R, trans) and 5-thia-1-azabicyclo[4.2.0.]oct-2-ene-7-amino-3-methyl-8-oxo- N-[2-phenyl-2(1H-pyrrolyl)acetyl]-2-carboxylic acid (6R, trans), in aqueous solution at 37 degrees C and at ionic strength of 0.5 mol.l-1 have been studied over the 2.3-11.5 pH range. In all cases, the hydrolysis of these compounds is subject to acid-base catalysis and, in some instances, to a general catalysis by various species present in the buffer solutions. The experimental results have been analyzed and discussed in relation to the hydrolytic mechanisms.     

Isolation, structural elucidation and characterization of impurities in Cefdinir

Three unknown impurities in Cefdinir bulk drug at levels below 0.2% (ranging from 0.05 to 0.2%) have been detected by high performance liquid chromatography (HPLC). These impurities were isolated from crude sample of Cefdinir using preparative HPLC. Based on the spectral data (NMR, IR and MS) the structures of these impurities were characterized as (6R, 7R)-7-[(z)-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-8-oxo-3-vinyl-5-thia-1-azabicyclo [4.2.0] oct-2-ene-2-carboxylic acid-5-oxide (I). (6R, 7R)-7-[(z)-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-8-oxo-3-vinyl-5-thia-1-azabi-cyclo [4.2.0] oct-3-ene-2-carboxylic acid (II). (6R, 7R)-7-[(z)-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]-8-oxo-3-methyl-5-thia-1-azabicyclo-[4.2.0]oct-2-ene-2-carboxylic acid (III), respectively. The origin and structural elucidation of all impurities have been discussed.     

比阿培南的合成

水合肼经缩合、烯丙基化、脱保护后甲酰化、溴加成、环合、取代、醇解、氧化、去甲酰化、环合、还原得到6，7-二氢-6-巯基-5H-吡唑并[1，2-a][1,2，4]三唑鎓氯化物（12），收率12％。12与（4R，5S，6S）-3-二苯氧磷酰氧基-6-[（1R）-1-羟乙基]-4-甲基-7-氧代-1-氮杂二环[3．2．0]庚-2-烯-2-羧酸对硝基苄酯（13）经缩合、脱保护得到比阿培南，收率67．5％（以13计）。     

(6R,7R)-7-[2-呋喃基(甲氧亚氨基)乙酰氨基]-3-羟甲基-8-氧代-5-硫杂-1-氮杂二环[420]辛-2-烯-2-甲酸的合成研究

目的　制备(6R,7R) - 7-[2 -呋喃基(甲氧亚氨基)乙酰氨基] - 3-羟甲基- 8-氧代- 5 -硫杂- 1-氮杂二环[4 2 0]辛- 2 -烯- 2 -甲酸。方法　通过7-氨基头孢烷酸的水解,生成去乙酰基7-氨基头孢烷酸,再与2 - (2 -呋喃基)- 2 -甲氧亚胺基乙酸氯反应进行7位氨基的酰化制备上述医药中间体。结果及结论　适宜的反应条件为:7-氨基头孢烷酸在- 2 5℃水解,与2 - (2 -呋喃基) - 2 -甲氧亚胺基乙酰氯在- 10℃反应,二者的摩尔比为1 0∶1. 15,收率可达80 %。     

Inactivation and inhibition of gamma-aminobutyric acid aminotransferase by conformationally restricted vigabatrin analogues

Four cyclohexene analogues of gamma-aminobutyric acid (GABA) and beta-alanine were designed as conformationally rigid analogues of the epilepsy and drug addiction drug vigabatrin and as potential mechanism-based inactivators of gamma-aminobutyric acid aminotransferase (GABA-AT). The corresponding cyclopentene analogues were previously reported to be inhibitors, but not inactivators, of GABA-AT (Qiu, J.; Pingsterhaus, J.; Silverman, R. B. J. Med. Chem. 1999, 42, 4725-4728). cis-3-Aminocyclohex-4-ene-1-carboxylic acid (3) and cis-2-aminocyclohex-3-ene-1-carboxylic acid (5) showed time- and concentration-dependent, irreversible inactivation of GABA-AT. In both cases, the inactivations are protected by substrate, indicating that they are active site-directed. trans-3-Aminocyclohex-4-ene-1-carboxylic acid (4) and trans-2-aminocyclohex-3-ene-1-carboxylic acid (6) are not inactivators but are competitive reversible inhibitors of GABA-AT. Unlike the cyclopentene analogues, there appears to be sufficient ring flexibility to allow inactivation to occur. The orientation of the carboxylic and amino groups of these analogues is important for their binding to GABA-AT. Molecular modeling of GABA-AT with 3-6 and molecular dynamics simulations with vigabatrin bound provide rationalizations for the inhibitory properties of these compounds.     

头孢匹胺的合成

目的 研究头孢匹胺的合成工艺。 方法 (R)2-(6-甲基-4-羟基吡啶-3-羰基)-氨基]-2-(4-羟基苯基)乙酸乙酯(NPA-Et)经水解、成盐得到(R)2-(6-甲基-4-羟基吡啶-3-羰基)-氨基]-2-(4-羟基苯基)乙酸钠( NPA-Na)。NPA-Na与7-TMCA,即：(6R,7R)3-(1-甲基-1H-四唑-5-硫代甲基)-8-氧代-5-硫杂-1-氮杂双环[4.2.0]辛-2-烯-2-羧酸)缩合得头孢匹胺粗品,再成三乙胺盐,转酸,得到头孢匹胺成品。结果 第一步收率84.6%,第二步收率69.3%。结论     

头孢克肟及其关键中间体7-AVCA的合成工艺改进

目的 研究头孢克肟及其关键中间体7-AVCA的合成工艺,以酶解法替代传统化学裂解法.方法 经工艺考察及改进,最终确定以GCLE为起始原料,经关键中间体7-AVCA制备头孢克肟适合于生产的工艺.结果 所制得的头孢克肟质量好,总收率为64%.其中采用的酶解法工艺不仅解决了环保治理的瓶颈问题,同时改进工艺获得的中间体7-AVCA的质最明显优于其他方法,优质的7-AVCA从源头上起到提高下游原料药头孢克肟产品的含量及稳定性,降低杂质的作用.头孢克肟的结构经1H-NMR、IR和UV分析确证,色谱纯度经HPLC检测大于99%.结论 本文工艺与文献相比,操作简化,收率提高,产品质量优异,节能环保,适合于产业化.     

抗惊厥药物普瑞巴林的合成工艺改进

目的合成手性抗惊厥药物普瑞巴林。方法以异戊醛和丙二酸为起始原料，经缩合、酯化、加成、还原得到外消旋体3-氨甲基-5．甲基己酸，用（S）-（＋）-扁桃酸拆分得到目标化合物。结果与结论目标化合物的总收率为22％，结构经IR、 ^13C-NMR、1H-NMR确证。该方法原料廉价易得，反应条件温和易控，国内未见报道。