1-环丙基-6,7-二氟-8-甲氧基-1,4-二氢-4-氧代喹啉羧酸乙酯精制方法的考察

目的：采用不同溶剂重结晶法对1－环丙基－6,7－二氟－8－甲氧基－1,4－二氢－4－氧代喹啉羧酸乙酯精制并对精制品进行质量分析,从而确定较理想的精制方法。方法：采用无水乙醇、甲醇、乙酸乙酯、丙酮作为重结晶溶剂,采用熔点、红外光谱、高效液相色谱法对精制品进行质量分析。结果：四种精制品的外观、熔点基本一致;IR光谱一致;纯度差异较大,丙酮精制品纯度为82．4％,其余三种均大于98％。结论：选用无水乙醇进行精制,产品纯度高。     

6,7-二氟-4-羟基-2-甲氧甲硫基-3-喹啉羧酸乙酯的合成

3,4-二氟苯胺在三乙胺存在下与二硫化碳生成芳基取代的二硫代氨基甲酸后与氯甲酸乙酯反应得到3,4-二氟苯基异硫氰酸酯,先后与由丙二酸二乙酯在无机碱中成的盐和氯甲基甲醚反应后加热环合,得到氟喹诺酮类抗菌剂普卢利沙星的中间体6,7-二氟-4-羟基-2-甲氧甲硫基-3-喹啉羧酸乙酯,总收率85.7%.     

1—环丙基—6，7—二氟—8—甲氧基—1，4—二氢—4—氧代喹啉羧酸乙酯的制备

合成1－环丙基－6,7－二氟－8－甲氧基－1,4－二氢－4－氧代喹啉羧酸乙酯。以2,4,5－三氟－3－甲氧基苯甲酸为起始原料,经酰氯化,缩合,脱羧,醚化,环丙胺置换,环合得本品。实验收率约48％。本方法制备工艺简单,易操作。     

5—氨基—1环丙基6,7,8—三氟—1,4—二氢—4—氧代—3—喹啉羧酸 …

由６－硝基－２,３,４,５＝四氟苯甲酸为原料,经酰氯化后与β－环丙基氨基丙烯酸乙酯反应,再经环合,还原得标题化合物（１）,总收率５１．６％,由五氟苯甲酸依同法可制得１－环丙基－５,６,７,８－四氯－１,４－二氢－４－氧代－３－喹啉羧酸乙酯（６ｂ）,总收率为４８．７％。     

硫酸二乙酯作乙基化剂制备-7氯-1-乙基-6-氟1,4-二氢-4-氧喹啉-3-羧酸的工艺改进

本文采用硫酸二乙酯与7-氯-6-氟-4-羟基喹啉-3-羧酸乙酯反应,然后用氢氧化钠液水解得7-氯-1-乙基-6-氟-1,4-二氢-4-氧喹啉-3-羧酸。其总收率为80％,此法降低了原料成本,简化了工艺,适合工业生产。     

4-氯-2-氧代-1,2-二氢喹啉-3-甲醛的合成工艺研究

目的 对4-氯-2-氧代-1,2-二氢喹啉-3-甲醛的合成工艺进行研究。方法 以苯胺为原料通过酯的氨解、环合、胺亚甲基化、水解反应得到目标化合物。结果 合成了目标化合物,并利用MS和¹H-NMR确证了结构,此路线所得产品收率为62.1%。结论 此路线操作简单,成本低廉,设计合理,收率高,适合该化合物的工业化生产。     

罗氟司特中间体3-环丙基甲氧基-4-二氟甲氧基苯甲醛的合成

目的研究罗氟司特中间体的合成。方法 3,4-二羟基苯甲醛依次与Boc酸酐和氯甲基环丙烷反应后得3-环丙基甲氧基-4-O-Boc-苯甲醛,脱掉Boc后再与二氟一氯甲烷醚化制得罗氟司特中间体3-环丙基甲氧基-4-二氟甲氧基苯甲醛。结果总收率约62%。结论本合成路线操作简单,成本低,有利于大规模制备。     

7—（3—羟基—1，5—二氮杂环庚烷—1—胺基）—1—环丙基—6—氟—1，4—二氢—4氧代喹啉—3—羧酸及其类似物的合成与抗菌活性

设计并合成了新化合物7－（3－羟基－1,5－二氮杂环庚烷－1－胺基）－1－环丙基－6－氟－1,4－二氢－4氧代喹啉－3－羧酸（5a)及其类似物5b-5d,采用标准二倍稀释法测定了其对26株有代表性的革兰氏阳性及革兰氏阴性菌的体外抗菌活性。结果表明化合物5a-5d对所测菌株的抑菌活性低于司帕沙星,而5a和5e则对革兰氏阳性菌金葡球菌有较高的活性,其最低抑菌浓度MIC值为0．125mg/L。     

1-烷基-6-氟-1,4-二氢-7-(4-酰基-1-哌嗪基)-4-氧代喹啉-3-羧酸类似物的合成及其抗菌活性

目的 设计合成具有广谱抗菌活性的含氟喹诺酮类化合物。方法 利用吡酮酸7位哌嗪基4位氮上存在的活性氢为反应修饰基点，与磺酰氯，酰氯，氯甲酸酯进行Schotten-Baumann酰基化反应设计合成一系列含有磺酰基、酰基和烷氧羰基类氟喹诺酮类似物。结果 合成了20个含有磺酰基、酰基和氧羰基的氟喹诺酮类似物，利用元素分析、核磁共振进行了结构确认。结论 合成了16个未见报道的新化合物，初步体外活性测试结果表明，其中的4个化合物有较高的生物活性。     

1-氨基-6-氟-1,4-二氢-4-氧代-7-(取代)哌嗪基-3-喹啉羧酸及其衍生物的合成与抗菌活性

近年来,氟喹诺酮类抗菌药物的研究发展十分迅速。早期的构效关系研究表明,N-1位取代基对抗菌活性至关重要,如在N-1位引入氨基,可增加亲水性,口服吸收好,药代动力学性质得到改善(如氨氟哌酸)。Chu等发现N-1位苯环的引入亦有很好的抗菌活性和优良的药代动力学性质(如双氟哌酸),这可能是由于苯环与喹诺酮母环共轭,产生π-电子效应从而增强了生物活性与组织的分布与吸收。     

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%。     

7-羟基-3,4-二氢-2(1H)-喹啉酮的合成及两个副产物的分离确证

目的 改进7-羟基-3，4-二氢-2（1H）-喹啉酮的合成方法。方法 以间氨基苯甲醚为原料，经N-酰化和分子内傅-克烃化反应合成。结果 合成了目标化合物，两步反应的总收率为59％，并且分离出第二步反应的两个副产物，它们的结构经波谱确证。结论 改进的合成方法适用于工业化生产。     

Analysis of potential phenylacetone precursors (ethyl 3-oxo-2-phenylbutyrate,methyl 3-oxo-4-phenylbutyrate,and ethyl 3-oxo-4-phenylbutyrate) by gas chromatography/mass spectrometry and their conversion to phenylacetone

Methyl 3-oxo-2-phenylbutyrate (MAPA) is a recently circulating precursor of phenylacetone (P2P), a precursor of amphetamine and methamphetamine. MAPA has a hybrid chemical structure of acetoacetic acid ester and P2P. Acetoacetic acid ester is de-esterified and decarboxylated to give the ketone by heating under acidic conditions; therefore, MAPA is presumed to be converted to P2P by such treatment. Considering that ethyl 3-oxo-2-phenylbutyrate (EAPA), methyl 3-oxo-4-phenylbutyrate (MGPA), and ethyl 3-oxo-4-phenylbutyrate (EGPA) have the same chemical features as MAPA, these three compounds are potential P2P precursors. The authors examined the analysis of these compounds by gas chromatography–mass spectrometry (GC-MS) and their conversion to P2P by heating under acidic and basic conditions. These compounds were remarkably decomposed into P2P during GC-MS analysis regardless of the injection method and injector temperature. EAPA and EGPA also caused ester exchange to methyl ester by injection of methanol solution. P2P production and transesterification were almost prevented by methoxime derivatization. These compounds were converted to P2P by heating under acidic conditions. The reaction of MGPA and EGPA proceeded quicker than that of EAPA. The important by-product associated with the reaction was phenylacetylcarbinol (formed from EAPA and MGPA), which will be converted to (pseudo)ephedrine, important methamphetamine impurities. By heating under basic conditions, MGPA and EGPA were converted to P2P but EAPA was mainly converted to phenylacetic acid. In the future, when these compounds are in circulation, our study will be useful for identifying and elucidating the synthetic method of P2P.     

6-氨基-3,4-二氢-2(1H)-喹啉酮的合成

苯胺用3-氯丙酰氯酰化得到N-苯基-3-氯丙酰胺,在AlCl3作用下闭环得到3,4-二氢-2(1H)-喹啉酮后,经HNO3/H2SO4硝化、Pd-C/H2还原反应得到6-氨基-3,4-二氢-2(1H)-喹啉酮,总收率79%(按实际反应的苯胺计).     

5-乙基-2,4-二氢-4-(2-苯氧乙基)-3H-1,2,4-三唑-3-酮的合成

丙酰肼与三光气缩合环化得到5-乙基-1,3,4-噁二唑-2(3H)-酮,继与2-苯氧乙胺反应后在碱性条件下环合得到抗抑郁药奈法唑酮中间体5-乙基-2,4-二氢-4-(2-苯氧乙基)-3H-1,2,4-三唑-3-酮,总收率66.3%.     

Absolute configuration,stability, and interconversion of 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine valine adducts and their phenylthiohydantoin derivatives

Pyrrolizidine alkaloid-containing plants are widespread in the world and probably the most common poisonous plants affecting livestock, wildlife, and humans. Pyrrolizidine alkaloids require metabolic activation to form dehydropyrrolizidine alkaloids that bind to cellular proteins and DNA leading to hepatotoxicity, genotoxicity, and tumorigenicity. At present, it is not clear how dehydropyrrolizidine alkaloids bind to cellular amino acids and proteins to induced toxicity. We previously reported that reaction of dehydromonocrotaline with valine generated four highly unstable 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP)-derived valine (DHP-valine) adducts that upon reaction with phenyl isothiocyanate (PITC) formed four DHP-valine-PITC adduct isomers. In this study, we report the absolute configuration and stability of DHP-valine and DHP-valine-PITC adducts, and the mechanism of interconversion between DHP-valine-PITC adducts.