4—溴—3，5—二甲氧基苯甲酸的合成工艺研究

目的：研究4－溴－3，5－二甲氧基苯甲酸合成新方法，方法：以天然原料没食子酸为起始原料，经甲基人与溴化反应合成4－溴－3，5－二甲氧基苯甲酸。结果：利用该合成路线得到了目标物质，总收率为31．4％，结论：该合成工艺还需要进一步研究所优化反应条件。提高反应收率。     

5,6-二甲氧基-1-吲酮的合成

目的：合成5,6－二甲氧基－1－吲酮（Ⅰ）,并对其合成工艺进行改进。方法：以3,4－二甲氧基苯甲醛为起始原料,经缩合、还原、环合等步骤制备而成。结果：三步反应的总收率达71．8％,合成产物经熔点和红外光谱确证。结论：此合成工艺简便,易于工业化生产。     

2,2-二甲基-5-羟甲基-1,3-二氧六环的合成

目的：探讨2,2-二甲基-5-羟甲基-1,3-二氧六环的合成方法。方法：以丙二酸二乙酯为原料,途经加成、保护、脱乙氧羰基和还原等4步反应合成（2）。结果与结论：实验操作简单,收率高;该方法为合成（2）的方法。     

盐酸雷洛昔芬的合成研究

目的 盐酸雷洛昔芬的合成。方法 以3-甲氧基苯硫酚为起始原料经过环合、脱甲氧基等反应，然后与4-[2-(1-哌啶基)乙氧基]苯甲酰氯发生Friedel—Crafts反应，最后在巯基乙醇作用下脱去甲基保护得到盐酸雷洛昔芬。结果 合成产物经熔点、元素分析、经红外光谱、核磁共振谱等分析确定，结构正确；与文献报道一致。结论 与其它方法比较，该合成工艺简便，原料易得，易于工业化生产。     

2-氨基咪唑硫酸盐的制备

目的：合成2－氨基咪唑硫酸盐。方法：以氨基乙醛缩甲醇制备的N－（2，2－二甲氧基乙基）胍硫酸盐经盐酸催化环合制得2－氨基咪唑硫酸盐。结果：产物结构经^1HNMR确证；溶点与文献一致；收率70％－81．5％。结论：该法成本低，反应条件温和，收率高，易于生产。     

地衣酚的新合成方法

以对（或邻）甲苯胺为原料，经溴代、脱氨、甲氧基化反应合成3，5－二甲氧基甲苯，再脱甲基即得地衣酚，总收率52．3％。     

4—溴—3，5—二甲氧基苯甲酸的合成热力学条件研究

目的：确定反应趋势,设计合理的合成路线,方法：以天然原料没食子 酸为起原料,经甲基化、溴化,水解合成4－溴－3,5－二甲氧基苯,结果：通过键能和生成热等热力学数据计算了基元反应和总包反应的反应热和自由能,△G=-45.3KJ/mol,结论：结果表明反应为热力学上有利反应。     

4-甲氧基-α-[(3-甲氧基苯基)硫代]苯乙酮合成工艺的改进

目的：用相转移方法合成４－甲氧基－α－「３－甲氧基苯基）硫代」苯乙酮。方法：采用甲苯做溶剂,４０％ＮａＯＨ为碱液,ＴＢＡＢ伙催化剂进行相转移反应。结果：此法操作简便并得到高收率的标题化合物。结论：改进的合成路线适合于工业化生产。     

1—（4—甲氧基）苯基—2—丙胺的合成

以对羟基苯乙酸为原料,采用了一条新路线合成了平喘药福莫特罗重要中间体1-（4-甲氧基）苯基-2-丙胺,反应总收率38%。方法操作简单、可行,适于实验室合成。     

3-（3，4-二甲氧基苯基）-6-甲基香豆素合成方法的改进

目的：探讨3-芳基取代香豆素衍生物的简易合成方法。方法：以5-甲基水杨醛和3,4-二甲氧基苯乙酸为原料,在醋酐和三乙胺条件下,经加热环合反应,合成3-（3,4-二甲氧基苯基）-6-甲基香豆素。结果：与文献方法相比,本法的一步反应收率从12％～33％提高到73．6％。结论：本法操作简单,收率高,更具实用性。     

注射用依匹必利的紫外分光光度法测定

目的:建立测定注射用依匹必利中s()-5-三丁基锡N-[甲基(1乙基2吡咯烷基)]2,3二甲氧基-苯甲酰胺(A)含量的测定方法。方法:紫外分光光度法,检测波长为299nm。结果:A在20～200μg·mL-1范围内,线性关系良好(r=0.9997),平均回收率为100.31％,RSD为0.54％。结论:紫外分光光度法测定注射用依匹必利中A的含量,简单快捷,结果满意,为药盒的质控提供了有效手段。     

顶空气相色谱法测定依匹必利原料药中有机溶剂残留量

目的:建立以顶空气相色谱法测定依匹必利原料药中3种有机溶剂甲醇、乙醚、三乙胺残留量的方法。方法:采用顶空进样法,以二甲基甲酰胺为溶剂,甲苯为内标,平衡温度70℃,平衡时间30min。气相色谱条件中采用OV1701色谱柱;程序升温:40℃维持2min,以5℃·min-1的速率升至180℃,维持10min;气化室温度为200℃,检测器温度为260℃;载气为氮气,流速为5mL·min-1。结果:甲醇、乙醚、三乙胺检测浓度线性范围分别为53.8～376.6、62.0～434.0、20.2～141.4μg·mL-1(r均>0.9949);回收率均>98.1%,RSD均<1.9%。样品中3种有机溶剂残留量甲醇<0.092%、乙醚<0.0021%、三乙胺<0.00015%。结论:所建立方法灵敏、准确、可靠,适用于依匹必利原料药中有机溶剂残留量的测定。     

Visualization of dopamine D3-like receptors in human brain with [125I]epidepride.

In sections of human brain containing the striatum (caudate, nucleus, putamen, nucleus accumbens) the competition for binding of [125I]epidepride by compounds with differing selectivity for dopamine D2 and D3 receptors was examined. Domperidone showed higher affinity for D2-like than D3-like sites whereas 7-OH-DPAT (7-hydroxy-2-(N,N-di-n-propylamino)tetralin) and quinpirole demonstrated the reverse selectivity. The pattern of [125I]epidepride binding in the presence of a high concentration of domperidone was negligible in the dorsal striatum but indicated islands of dense binding to D3-like receptors in the nucleus accumbens and ventral putamen.     

Forced degradation behavior of epidepride and development of a stability-indicating method based on liquid chromatography–mass spectrometry

A reversed-phase high-performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was applied to study the forced degradation behavior and stability of epidepride. ¹²³I radioisotope-labeled epidepride, [(−)-N-{[(2S)-1-ethylpyrrolidin-2-yl]methyl}-5-iodo-2,3-dimethoxybenzamide] is a radiotracer with a high affinity for dopamine D₂ receptors in the brain and has been used as an imaging agent for single-photon emission computed tomography. HPLC studies were performed using ¹²⁷I-epidepride (the nonradioactive compound), instead of ¹²³I-epidepride, with an RP-18 column using a mobile phase consisting of methanol, acetonitrile, and ammonium acetate (pH 7.0, 10 mM). The eluent flow rate and the wavelength for HPLC detection were 0.5 mL/min and 210 nm, respectively. The ligand was exposed to acid (1 N HCl) and alkaline (1 N NaOH) media and was subjected to oxidative decomposition at room temperature using 3% H₂O₂ and to thermal decomposition at 50°C. After various reaction times (30 minutes, 1 hour, 2 hours, 8 hours, and 24 hours), the substances were investigated by HPLC and LC-MS/MS. Although no decomposition products were observed after the acidic, alkaline, and thermal treatments, > 80% of the initial amount of ¹²⁷I-epidepride was oxidized within 24 hours in the presence of H₂O₂. Only one major oxidation product with an m/z value of 435 was observed, in addition to the ¹²⁷I-epidepride species (m/z 419). The product was characterized by LC-MS/MS fragmentation, and the deteriorated type and fragmentation pathways were proposed for epidepride.     

Imaging extrastriatal dopamine D(2) receptor occupancy by endogenous dopamine in healthy humans

The effect of endogenous dopamine on in vivo measurement of dopamine D(2) receptors in extrastriatal regions (thalamus and temporal cortex) was evaluated with single photon emission computed tomography and the high affinity ligand [123I]epidepride by comparing the binding potential before and after acute dopamine depletion. Dopamine depletion was achieved by per-oral administration of 5.5 g/70 kg body weight alpha-methyl-para-tyrosine given in 37 h. The alpha-methyl-para-tyrosine treatment increased the binding potential significantly in the temporal cortex (13+/-15%, P=0.036) but not in the thalamus (2+/-9%). The increase of the binding potential in the temporal cortex correlated strongly with the increase of dysphoric mood evaluated by the Positive and Negative Symptom Scale (PANSS) (rho=0.88, P=0.004). These results imply that [123I]epidepride, coupled with acute dopamine depletion might provide estimates of synaptic dopamine concentration.     

The discovery of epidepride and its analogs as high-affinity radioligands for imaging extrastriatal dopamine D(2) receptors in human brain

[(123)I]Epidepride, [(18)F]fallypride, and [(76)Br]isoremoxipride (FLB-457) and their corresponding [(11)C]labeled derivatives belong to a class of high-affinity radioligands for SPECT or PET imaging of dopamine D(2) receptors in the human brain. In contrast to previously used imaging agents, these ligands are capable of identifying extrastriatal dopamine D(2) receptors. The design of these substituted benzamides derive its origin from the atypical antipsychotic agent, remoxipride. Starting in the late 1970's, halogenated analogs of (S)-sulpiride were evaluated in binding assays and behavioral studies, leading to the discovery of remoxipride. Remoxipride was 10 times weaker than sulpiride in vitro but 50 times more potent in vivo. Search for a putative active metabolite of remoxipride led to the discovery of raclopride and eticlopride, the former becoming a useful radioligand as tritium or carbon-11 labeled form for receptor binding and PET studies, respectively. In the US, the mono-iodine analog of raclopride, [(123)I]iodobenzamide (IBZM), was found to have moderate putamen-to-cerebellum ratio in rat and human brain. Continued search for metabolites of remoxipride led to the discovery of its 3,6-dihydroxy derivative, NCQ-344, with an extremely potent in vivo activity in the rat. SAR studies of the metabolites of remoxipride led to the discovery of the 3-methoxy isomer, isoremoxipride (FLB-457) and its corresponding 6-hydroxy analog, FLB-463, both having affinities for the dopamine D(2) receptor in the 20-30 pM range. Later, the 5-[(123)I]iodo analog of FLB-463, [(123)I]ioxipride ([(123)I]NCQ-298), became a potential SPECT imaging agent. In the mean time, the deshydroxy analog of IBZM, [(125)I]iodopride, showed binding potential in the rat similar to [(125)I]IBZM. Epidepride was designed by combining the structure of isoremoxipride with that of iodopride. In 1988, epidepride was independently prepared and radiolabeled in three separate laboratories in Stockholm, Berkeley, and Nashville. Evaluation of seven [(125)I]iodine substituted analogs of raclopride, including IBZM, revealed the unusual high striatum-to-cerebellum ratio of 234 of [(125)I]epidepride in the rat. Subsequent SPECT images with [(123)I]epidepride demonstrated its ability to identify extrastriatal dopamine D(2) receptors in the human brain. Exploration of the structure of epidepride confirmed its exceptional properties, to be exceeded only by its N-allyl homolog, [(125)I]nalepride. The design by others of a series of potent 5-(3-[(18)F]fluoropropyl) substituted analogs of epidepride for PET imaging, lead to the discovery of [(18)F]fallypride. By elucidating the role of lipophilicity in the substituted benzamides, the excellent imaging characteristics of [(11)C]/[(123)I]epidepride, [(11)C]/[(76)Br]isoremoxipride and [(18)F]fallypride, could not only be explained but predicted with remarkable accuracy. By using the inverse product of the receptor affinity (K(D)), and the apparent partition constant of the radioligand (P((7.4))), estimates of maximal binding potential of any radioligand for imaging of any neurotransmitter receptor or transporter site seem possible.     

Forced degradation behavior of epidepride and development of a stability-indicating method based on liquid chromatography–mass spectrometry

A reversed-phase high-performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was applied to study the forced degradation behavior and stability of epidepride. ¹²³I radioisotope-labeled epidepride, [(-)-N-{[(2S)-1-ethylpyrrolidin-2-yl]methyl}-5-iodo-2,3- dimethoxybenzamide] is a radiotracer with a high affinity for dopamine D₂ receptors in the brain and has been used as an imaging agent for single-photon emission computed tomography. HPLC studies were performed using ¹²⁷I-epidepride (the nonradioactive compound), instead of ¹²³I-epidepride, with an RP-18 column using a mobile phase consisting of methanol, acetonitrile, and ammonium acetate (pH 7.0, 10 mM). The eluent flow rate and the wavelength for HPLC detection were 0.5 mL/min and 210 nm, respectively. The ligand was exposed to acid (1 N HCl) and alkaline (1 N NaOH) media and was subjected to oxidative decomposition at room temperature using 3% H₂O₂ and to thermal decomposition at 50°C. After various reaction times (30 minutes, 1 hour, 2 hours, 8 hours, and 24 hours), the substances were investigated by HPLC and LC-MS/MS. Although no decomposition products were observed after the acidic, alkaline, and thermal treatments, >80% of the initial amount of ¹²⁷I-epidepride was oxidized within 24 hours in the presence of H₂O₂. Only one major oxidation product with an m/z value of 435 was observed, in addition to the ¹²⁷I-epidepride species (m/z 419). The product was characterized by LC-MS/MS fragmentation, and the deteriorated type and fragmentation pathways were proposed for epidepride.     

Visualization of extrastriatal dopamine D2 receptors in the human brain.

[123I]Epidepride, a potent and selective dopamine D2 radioligand, was administered to a 27 year old normal male volunteer. Single photon tomography revealed that peak striatal uptake occurred at 4 h after injection with a striatal:cerebellar ratio of 7.8 rising to over 100 at 18 h post injection. Uptake above the levels seen in cerebellum was also noted in the thalamus, pituitary, hypothalamus and temporal lobe, particularly medially. Single photon tomography with [123I]epidepride allows visualization of extrastriatal dopamine D2 receptors in man.     

Striatal and temporal cortical D2/D3 receptor occupancy by olanzapine and sertindole in vivo: a [123I]epidepride single photon emission tomography (SPET) study

RATIONALE: Previous work suggests clozapine preferentially targets limbic cortical dopamine systems, which could help account for its lack of extrapyramidal side effects (EPS) and superior therapeutic efficacy. OBJECTIVES: To test the hypothesis that olanzapine, a novel atypical antipsychotic drug, occupies temporal cortical D2/D3 receptors to a greater extent than striatal D2/D3 receptors in vivo. METHODS: Nine schizophrenic patients taking either olanzapine [(n=5; mean (SD) age: 32.5 (6.5) years; daily dose: 18.3 (2.6) mg] or sertindole [(n=4; mean (SD) age: 30.3 (7.4) years; daily dose: 16 (5.6) mg] were studied with [123I]epidepride ((S)-N-[(1-ethyl-2-pyrrolidinyl)methyl]-5-iodo-2,3-dimethoxybenz amide) and single photon emission tomography (SPET). An estimate of [123I]epidepride 'specific binding' to D2/D3 receptors was obtained in patients and age-matched healthy volunteers. A summary measure was generated representing striatal and temporal cortical relative %D2/D3 receptor occupancy by antipsychotic drugs. Occupancy data were compared with previously studied groups of patients receiving typical antipsychotic drugs (n=12) and clozapine (n=10). RESULTS: Mean striatal and temporal cortical %D2/D3 receptor occupancy in olanzapine-treated patients was 41.3% (SD 17.9) and 82.8% (SD 4.2), respectively. Unexpectedly low levels of striatal relative %D2/D3 receptor occupancy were seen in two patients with typical antipsychotic-drug-induced movement disorder prior to switching to olanzapine. In the temporal cortex, mean D2/D3 dopamine receptor occupancy levels above 80% were seen for all antipsychotic drugs studied. CONCLUSIONS: The atypical antipsychotic drugs olanzapine and sertindole, in common with clozapine, demonstrate higher occupancy of temporal cortical than striatal D2/D3 dopamine receptors in vivo at clinically useful doses. This could help mediate their atypical clinical profile of therapeutic efficacy with few extrapyramidal side effects. Limbic selective blockade of D2/D3 dopamine receptors could be a common action of atypical antipsychotic drugs.     

Effect of haloperidol and clozapine on the density of “perforated” synapses in caudate,nucleus accumbens,and medial prefrontal cortex

Perforated synapses, which contain a discontinuous density along the postsynaptic membrane, can increase or decrease in numbers following various behavioral and biochemical manipulations. We have previously established that 14-day treatment with haloperidol causes an increase in the number of perforated synapses within the caudate nucleus (dorsolateral region) but not the nucleus accumbens (Meshul and Casey 1989). This effect was reversed if the animals were withdrawn from the drug for an equivalent period of time. We have now further examined the effects of haloperidol administration, which is associated with a high incidence of extrapyramidal side effects (EPS) and tardive dyskinesia (TD), and assessed the effects of clozapine, which appears to have a lower potential for inducing EPS and TD. Administration of haloperidol for 2 weeks significantly increased the percentage of perforated synapses in the caudate, but not in the nucleus accumbens or layer VI of medial prefrontal cortex (MPCx). There was an increase in specific [¹²⁵I]epidepride binding to D-2 receptors in the caudate nucleus and MPCx following haloperidol. Administration of clozapine for 2 weeks did not affect the percentage of perforated synapses in any of the three dopamine (DA)-rich regions that were examined. There was an increase in specific [³H]SCH 23390 binding to D-1 receptors and in specific [¹²⁵I]epidepride binding to D-2 receptors only within MPCx following clozapine. The absence of any change in the density of perforated synapses within the dorsolateral caudate nucleus following clozapine correlates with: 1) the lack of effect on specific DA receptor binding or down regulation of serotonin (5-HT₂) receptors (as reported by others), or 2) the inability in clozapine-treated animals to depolarize block substantia nigra (A9) DA neurons. These results may be related to the low incidence of EPS and TD observed with clozapine.