奥美沙坦酯关键中间体的合成工艺改进

目的优化奥美沙坦酯关键中间体的合成工艺。方法以4-(1-羟基-1-甲基乙基)-2-丙基咪唑-5-羧酸乙酯为原料,与4-[2-(2-三苯甲基四唑-5-基)苯基]苄基溴缩合合成关键中间体4-(1-羟基-1-甲基乙基)-2-丙基-1-[2'-(三苯甲基四唑-5-基)联苯基-4-基甲基]咪唑-5-羧酸乙酯。结果与结论该优化的合成方法操作简便,制备的中间体收率为55%,质量较好。     

4-(1-羟基-1-甲基乙基)-2-丙基-1H-咪唑-5-羧酸乙酯的合成

2-甲基-2-羟基丙腈(2)经三甲基硅基(TMS)保护后,经Blaise反应并脱三甲基硅烷基保护,在亚硝酸钠和乙酸作用下肟化和Pd/C催化还原得到2-氨基-4-羟基-4-甲基-3-氧代戊酸乙酯三氟乙酸盐,再与丁酰亚氨酸甲酯盐酸盐环合得到奥美沙坦酯关键中间体4-(1-羟基-1-甲基乙基)-2-丙基-1H-咪唑-5-羧酸乙酯,总收率约40%。     

奥美沙坦酯合成路线图解

奥美沙坦酯(olmesartan medoxomil,1),化学名为4-(1-羟基-1-甲基乙基)-2-丙基-1-[[2'-(1H-四唑-5-基)联苯-4-基]甲基]咪唑-5-羧酸(5-甲基-2-氧代-1,3-二氧杂环戊烯-4-基)甲基酯,是由日本Sankyo公司研发的一种AT_1受体拮抗剂,2002年5月美国FDA批准用于治疗高血压.本品对不同程度的高血压降压作用均较好,患者耐受性好.     

Benicar

[通用名称] olmesartan medoxomil,奥美沙坦酯[化学名称]4-(1-羟基-1-甲基乙基)-2-丙基-1-[[2’-(1氢-四唑基-5)[1，1’-二苯基]-4-]甲基]咪唑-5-羧酸(5-甲基-2-氧-1，3-二氧环戊烯基-4-)甲酯[理化性状]为白色或亮黄白色结晶性粉末，部分溶于水，在甲醇中溶解度小。     

替米沙坦关键中间体的新合成路线

本研究设计了替米沙坦关键中间体2-正丙基-4-甲基-6-(1-甲基苯并咪唑-2-基)苯并咪唑(1)的新合成路线。正丁腈(2)与甲醇或乙醇在氯化氢作用下反应得到正丁基亚胺酯(3)的盐酸盐,经碱化得到游离的3,再与4-氨基-3-甲基苯甲酸(4)反应得到4-丁脒基-3-甲基苯甲酸(5)。5与次氯酸钠反应生成中间过渡产物,然后直接在氢氧化钠作用下关环生成2-正丙基-4-甲基苯并咪唑-6-羧酸(6)。6与N-甲基邻苯二胺盐酸盐(7)脱水缩合生成1。该路线采用了2次叠缩工艺,简化了生产操作,总收率高达79%(以4计)。     

奥美沙坦酯及其相关物质的分离与测定

目的：建立反相高效液相色谱法分离测定奥美沙坦酯及其相关物质。方法：HPLC色谱条件：色谱柱为Inertsil ODS-2（4．6mm×250mm，5μm），柱温为25℃；以乙腈-磷酸盐缓冲液为流动相，进行梯度洗脱；流速为1．0mL·min^-1；检测波长为240nm。结果：明确了奥美沙坦酯合成中可能引入的杂质A，B，C，D，E以及奥美沙坦酯的出峰位置；杂质A，B，C，D，E的校正因子（相对于奥美沙坦酯）分别为0．90，0．88，1．07，1．04，1．13；在奥美沙坦酯原料中共检测到6个杂质，其中杂质A和杂质D含量均大于0．1％。结论：采用加校正因子的1％主成分自身对照法和杂质外标对照法均能直接反映奥美沙坦酯中相关物质情况。     

抗高血压药坎地沙坦酯的新合成方法

目的 合成抗高血压药坎地沙坦的前药坎地沙坦酯。方法 以三苯甲基坎地沙坦为起始原料, 经酯化、脱保护基得到1-氯乙基-2-乙氧基-3-[(2’-(1H-四氮唑-5-基)联苯基-4-基)甲基]-3H-苯并咪唑-4-酯,该中间体与环己基碳酸单酯反应得到candesartan cilexitil。结果与结论 总收率为42.1%,目标化合物的结构经核磁共振氢谱,质谱确证。     

2-正丁基-5-甲酰基咪唑的合成

目的合成抗高血压药伊普沙坦的关键中间体2-正丁基-5-甲酰基咪唑。方法乙二胺与戊腈在硫粉的作用下环合得到2-正丁基咪唑啉（2），经脱氢、碘化、还原、羟甲基化、氧化、催化氢解得到目标化合物2-正丁基-5-甲酰基咪唑（1）。结果与结论目标化合物的结构经MS、^1H-NMR谱确证，优化后的合成路线，所用试剂易得、操作简单、反应条件温和，总收率为10．8％。     

咪唑并［2,1-b］［1,3,4］噻二唑及杂环氨曼尼希碱盐酸盐的合成及抗菌活性

为了进一步优化由噻二唑核稠合的水溶性稠杂环化合物的合成方法及抗菌活性，本文用2-(4-甲氧苯基)-5-氨基-1,3,4-噻二唑(2)与α-氯代-4-氯苯乙酮(3)缩合得6-(4-氯苯基)-2-(4-甲氧苯基)-咪唑并［2,1-b］［1,3,4］噻二唑(4)，4与取代哌嗪发生亲核取代反应得到6-(4-取代哌嗪-1-苯基)-2-(4-甲氧苯基)-咪唑并［2,1-b］-［1,3,4］噻二唑(5)，5与杂环氨进行曼尼希反应并与盐酸成盐得目标化合物6-(4-取代哌嗪-1-苯基)-2-(4-甲氧苯基)-5-杂环氨基甲基-咪唑并［2,1-b］［1,3,4］噻二唑盐酸盐(1)。用试管二倍稀释法评价了15个新化合物的体外抗菌活性，结果表明，随着极性基团的引入，抗菌活性显著提高，提示该类化合物的结构修饰值得进一步研究。     

奥美沙坦酯的工艺改进

目的 改进奥美沙坦酯的合成工艺。方法 以2-氰基-4''-甲基联苯(2)为起始原料,经溴代反应,“一锅法”完成N-烷基化和皂化-酯化反应,再经氰基四氮唑化反应,得到奥美沙坦酯(1)。结果 3步得到成品,总收率46.5%(以2-氰基-4''-甲基联苯计)。结论 改进后的工艺非常实用,适合工业化生产。     

伊曲康唑区域和几何异构体的合成及结构阐明

以顺式或反式-[2-溴甲基-2-(2，4-二氯苯基)-1，3-二氧戊环-4-基]甲醇苯甲酸酯为原料，经与三唑缩合、水解、柱色谱纯化、甲磺酰化，最后与4-[4-[4-(4-羟基苯基)-1-哌嗪基]苯基]-2，4-二氢-2-(1-甲基丙基)-3H-1，2，4-三唑-3-酮缩合，可分别得到抗真菌药物伊曲康唑(1)的区域异构体2或几何异构体3。比较1、2和3的^1HNMR谱学特征。2和3可作为1质量控制的对照物。     

Clinical and experimental aspects of olmesartan medoxomil, a new angiotensin II receptor antagonist

Olmesartan medoxomil is a new orally active angiotensin II (Ang II) type 1 receptor antagonist. It is a prodrug and is rapidly de-esterified during absorption to form olmesartan, the active metabolite. Olmesartan is a potent, competitive and selective Ang II type 1 receptor antagonist. Olmesartan is not metabolized by the cytochrome P-450 and has a dual route of elimination, by kidneys and liver. In patients with essential hypertension olmesartan medoxomil administered once daily at doses of 10-80 mg dose-dependently reduced diastolic blood pressure (DBP). Troughto-peak ratios for both DBP and systolic blood pressure (SBP) were above 50%. At the recommended once-daily starting doses, olmesartan medoxomil (20 mg) was more effective than losartan (50 mg), valsartan (80 mg) or irbesartan (150 mg) in reducing cuff DBP in patients with essential hypertension. The results of cuff SBP and mean 24-h DBP and SBP were similar to those of cuff DBP measurement. In mild-to-moderate hypertensive patients the recommended starting dose of olmesartan medoxomil was as effective as that of amlodipine besylate (5 mg/day) in reducing both cuff and 24-h blood pressure. In lowering DBP olmesartan medoxomil, at 10-20 mg/day, was as effective as atenolol at 50-100 mg/day. In mild-to-moderate hypertensive patients, olmesartan medoxomil, at 5-20 mg once daily, was more effective than captopril at 12.5-50 mg twice daily. At 20-40 mg once daily olmesartan medoxomil was as effective as felodipine, at 5-10 mg once daily. Olmesartan medoxomil has minimal adverse effects with no clinically important drug interactions. Animal studies have shown that olmesartan medoxomil provides a wide range of organ protection. Olmesartan medoxomil ameliorated atherosclerosis in hyperlipidemic animals and ameliorated cardiac remodeling and improved survival in rats with myocardial infarction. Olmesartan medoxomil has renoprotective effects in a remnant kidney model and type 2 diabetes models. Future investigation should reveal whether these beneficial effects of olmesartan medoxomil are applicable to human diseases.     

The preferential inhibitory effect of olmesartan,a new angiotensin II type 1 antagonist,on sympathetic nerve terminals in isolated canine splenic artery

Effects of olmesartan (RNH-6270: (5-methyl-2-oxo-1,3-dioxolen-4-yl)methoxy-4-(1-hydroxy-1-methylethyl)-2-propyl[4-[2-(tetrazol-5-yl)-phenyl]phenyl]methylimidazol-5-carboxylase, an active form of olmesartan medoxomil (CS-866)) was investigated in isolated, perfused canine splenic arterial preparations. Neither exogenous noradrenaline- nor ATP-induced vasoconstrictor responses were modified by treatment with the used concentrations of olmesartan (1-100 nM). A high concentration of 10 nM angiotensin II caused a potentiation of either noradrenaline- and ATP-induced constrictions, although 1 nM angiotensin II did not induce any potentiating effects for these responses. These potentiations were inhibited by olmesartan in a concentration-related manner. Periarterial nerve electrical stimulation (PNS) readily induced a biphasic constriction consisting of an initial P2X purinoceptor-mediated vasoconstriction followed by a prolonged mainly alpha(1)-adrenoceptor-mediated response. PNS-induced 1st and 2nd peaked responses were significantly inhibited by olmesartan in a concentration-related manner. With a low concentration of 1 nM angiotensin II, which did not induce any vascular effects by itself, PNS-induced responses were markedly enhanced. The enhanced responses were inhibited by olmesartan. It is concluded that endogenous angiotensin II exerts its stimulating action on the releases of ATP and noradrenaline from the periarterial sympathetic nerve terminal, and olmesartan has an inhibitory property on angiotensin II-induced potentiation of endogenous ATP- and noradrenaline-induced responses.     

Efficacy and Safety of Olmesartan Medoxomil and Hydrochlorothiazide Compared with Benazepril and Amlodipine Besylate

BACKGROUND: Most patients with stage 2 hypertension require two or more antihypertensive agents in order to achieve the BP goals recommended in current treatment guidelines. Accordingly, combinations of two drugs with different mechanisms of antihypertensive action are widely used. OBJECTIVE: The aim of this randomized, double-blind, multicenter 12-week study was to compare the efficacy, safety, and tolerability of a combination of olmesartan medoxomil/hydrochlorothiazide (HCTZ) with that of benazepril plus amlodipine besylate in patients with stage 2 hypertension. METHODS: Patients were eligible for randomization following a 3- to 4-week placebo run-in period if they had either (i) mean seated DBP>or=90 mm Hg but<115 mm Hg and mean seated SBP>or=160 mm Hg but <200 mm Hg, or (ii) mean seated DBP>or=100 mm Hg but<115 mm Hg. The difference in mean seated SBP measured on two separate visits during the run-in period was required to beor=95 mm Hg and<115 mm Hg or SBP>145 mm Hg and相似文献   

Blood pressure reduction with olmesartan in mild-to-moderate essential hypertension: a planned interim analysis of an open label sub-study in German patients

OBJECTIVE: To present the baseline characteristics and open-label treatment phase results for German patients in OLMEBEST, a European, multinational, partially randomized, partially double-blind study in patients with mild-to-moderate essential hypertension. RESEARCH DESIGN AND METHODS: After a 2-week placebo run-in, patients received olmesartan 20 mg for 8 weeks. Controlled patients (mean sitting diastolic blood pressure [sDBP] < 90 mmHg) continued on olmesartan 20 mg/day for a further 4 weeks. Non-controlled patients (sDBP > 90 mmHg) were randomized to olmesartan 40 mg/day or olmesartan 20 mg/day plus 12.5 mg hydrochlorothiazide for 4 weeks. Of 823 patients included, 558 continued olmesartan 20 mg treatment and 228 patients were randomized to olmesartan 40 mg/day or combination therapy. Efficacy variables included the change from baseline in mean sitting DBP and systolic blood pressure [sSBP] at Week 8 (and Week 12 for controlled patients), and the proportion of controlled patients and responders (mean sDBP < 90 mmHg or improvement of > 10 mmHg from baseline at Week 8). RESULTS: After 8 weeks of olmesartan medoxomil 20 mg, mean reduction from baseline in sDBP was 11.8 mmHg and in sSBP was 17.1 mmHg. In controlled patients continuing open-label olmesartan medoxomil 20 mg, mean reduction from baseline at 12 weeks in sDBP was 14.9 mmHg and in sSBP was 20.1 mmHg. At Week 8, the response rate was 76% and the control rate was 70%. Olmesartan medoxomil 20 mg/day was well tolerated; 30.9% of patients experienced an adverse event, and the majority of these events were judged by the investigators to be mild. CONCLUSION: Olmesartan medoxomil monotherapy at the recommended dosage of 20 mg once daily is effective and well tolerated in patients with mild-to-moderate hypertension.     

Effects of olmesartan medoxomil as an angiotensin II-receptor blocker in chronic hypoxic rats

We established a rat chronic alveolar hypoxia in vivo model to evaluate the efficacy against hypoxic pulmonary hypertension of a new angiotensin II-receptor I blocker, olmesartan medoxomil. Three groups of rats were established: rats exposed for 2-6 weeks to 10% oxygen atmosphere in a normobaric chamber; hypoxic rats treated with olmesartan medoxomil oral administration (5 mg/day) every day; and control rats fed in a normoxic condition. After hypoxia treatment, the presence, etiology and severity of pulmonary hypertension, was echocardiographically evaluated, and expressions of brain natriuretic peptide (BNP), transforming growth factor (TGF-beta) and endothelin-1 genes measured by both immunohistochemical assay and real-time polymerase chain reaction. Olmesartan medoxomil significantly reduced the induction of hypoxic cor pulmonale not only on echocardiographical observations but also in BNP, TGF-beta and endothelin gene expressions in molecular studies. However, systolic blood pressure was independent of olmesartan medoxomil. The present study clearly indicates that the angiotensin II-type I-receptor blocker olmesartan medoxomil has significant efficacy for hypoxic cor pulmonale.     

Antihypertensive, insulin-sensitising and renoprotective effects of a novel, potent and long-acting angiotensin II type 1 receptor blocker, azilsartan medoxomil, in rat and dog models

The pharmacological profile of a novel angiotensin II type 1 receptor blocker, azilsartan medoxomil, was compared with that of the potent angiotensin II receptor blocker olmesartan medoxomil. Azilsartan, the active metabolite of azilsartan medoxomil, inhibited the binding of [(125)I]-Sar(1)-I1e(8)-angiotensin II to angiotensin II type 1 receptors. Azilsartan medoxomil inhibited angiotensin II-induced pressor responses in rats, and its inhibitory effects lasted 24h after oral administration. The inhibitory effects of olmesartan medoxomil disappeared within 24h. ID(50) values were 0.12 and 0.55 mg/kg for azilsartan medoxomil and olmesartan medoxomil, respectively. In conscious spontaneously hypertensive rats (SHRs), oral administration of 0.1-1mg/kg azilsartan medoxomil significantly reduced blood pressure at all doses even 24h after dosing. Oral administration of 0.1-3mg/kg olmesartan medoxomil also reduced blood pressure; however, only the two highest doses significantly reduced blood pressure 24h after dosing. ED(25) values were 0.41 and 1.3mg/kg for azilsartan medoxomil and olmesartan medoxomil, respectively. In renal hypertensive dogs, oral administration of 0.1-1mg/kg azilsartan medoxomil reduced blood pressure more potently and persistently than that of 0.3-3mg/kg olmesartan medoxomil. In a 2-week study in SHRs, azilsartan medoxomil showed more stable antihypertensive effects than olmesartan medoxomil and improved the glucose infusion rate, an indicator of insulin sensitivity, more potently (≥ 10 times) than olmesartan medoxomil. Azilsartan medoxomil also exerted more potent antiproteinuric effects than olmesartan medoxomil in Wistar fatty rats. These results suggest that azilsartan medoxomil is a potent angiotensin II receptor blocker that has an attractive pharmacological profile as an antihypertensive agent.     

Synthesis and pharmacological investigation of novel 1-substituted-4-(4-substituted phenyl)-4H-[1,2,4]triazolo[4,3-a]quinazolin-5-ones as a new class of H1-antihistamine agents

A series of novel 1-substituted-4-(4-substituted phenyl)-4H-[1,2,4]triazolo[4,3-a]quinazolin-5-ones was synthesized by the cyclization of 2-hydrazino-3-(4-substituted phenyl)-3H-quinazolin-4-one with various one-carbon donors. The starting material, 2-hydrazino-3-(4-substituted phenyl)-3H-quinazolin-4-one, was synthesized from 4-substituted aniline by a novel innovative route. When tested for in-vivo H1-antihistamine activity on conscious guinea-pigs, all the test compounds significantly protected the animals against histamine-induced bronchospasm. The compound 1-methyl-4-(4-chloro phenyl)-4H-[1,2,4]triazolo[4,3-a]quinazolin-5-one (VII) was more potent (72.71% protection), and 1-methyl-4-(4-methoxy phenyl)-4H-[1,2,4]triazolo[4,3-a]quinazolin-5-one (II) was equipotent (71% protection), when compared with the reference standard, chlorpheniramine maleate (71% protection). Compounds II and VII showed negligible sedation (5% and 8% respectively) when compared with chlorpheniramine maleate (25%). Compounds II and VII could serve as prototype molecules for further development as a new class of H1-antihistamines.     

奥美沙坦酯与缬沙坦治疗中度原发性高血压临床研究

目的比较奥美沙坦酯和缬沙坦治疗中度原发性高血压的疗效和安全性。方法入选482例中度原发性高血压患者,按照1∶1随机分组,分别接受奥美沙坦酯20～40 mg/d或缬沙坦80～160 mg/d治疗,共8周。观察并比较其降压效果。结果治疗4周后,奥美沙坦酯组SeDBP平均下降了(10.58±6.82)mmHg,缬沙坦组下降了(9.38±7.16)mmHg;两组比较,P=0.004。奥美沙坦组与缬沙坦组分别有60%、61.74%的患者剂量加倍,加量有效率分别为52.22%、51.85%;治疗8周后,两组SeDBP平均下降(15.72±6.03)mmHg及(14.12±6.79)mmHg;治疗4周后,两组的药物不良反应发生率分别为3.33%、7.5%(P>0.05)。结论口服奥美沙坦酯胶囊20～40 mg/d,1次/d,能保持24 h平稳降压,8周总有效率为79.65%;与缬沙坦80～160 mg/d的降压疗效相近。而两组药物不良反应发生率差异无统计学意义。