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用一种新的简便方法对Verbenachalcone进行全合成, 针对目标物的结构特征, 将其切为2个合成片段, 即化合物4和6, 然后再将2个片段连接. 从对羟基苯甲醛(2)开始经过溴代、乙酰化、Ullmann反应、甲氧甲基化、羟醛缩合、脱保护和催化加氢等7步反应完成了标题化合物的全合成, 总收率为39.1%, 合成的关键步骤是3-溴-4-羟基苯甲醛(3)和香兰素进行的Ullmann反应. 关键中间体与最终产物的化学结构经1H NMR, 13C NMR和ESI-MS等表征确认. 相似文献
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探索了一条合成苯磺酸贝他斯汀的新路线。以2-吡啶甲酸、氯苯为原料,经过9步反应合成苯磺酸贝他斯汀,其中关键消旋中间体(4-氯苯基)(2-吡啶基)甲氧基哌啶,经过D-DBTA拆分,可得到光活性(S)-(4-氯苯基)(2-吡啶基)甲氧基哌啶(>99% ee)。同时,(R)-(4-氯苯基)(2-吡啶基)甲氧基哌啶经过消旋化后再次拆分得到(S)-构型产物。该合成方法反应条件温和,具有工业化生产前景。最终产物结构由1H NMR, 13C NMR和HR-MS(ESI)确证。
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本文报道了3-亚甲基异苯并呋喃-1(3H)-酮的高效合成方法。其特点是以邻甲基苯甲酸为原料,采用"一锅法"经过酯化,自由基溴代,形成季鏻盐三步反应得到2-[(溴三苯基正膦基)甲基]苯甲酸甲酯;随后经过改进的Wittig反应,酯水解合成了邻乙烯基苯甲酸;再与KI/I2溶液发生环合反应生成3-碘甲基异苯并呋喃-1(3H)-酮;最后发生消除反应得到所需要的产物。该方法具有原料易得、价格低廉、反应条件温和、收率高等优点。化合物结构用1H NMR、13C NMR和IR表征。 相似文献
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研究了三氟化硼乙醚(BF3·OEt2)催化2-(N-取代氨基甲酰基甲基氨基)苯甲醇与醛的反应,发展了合成取代3,1-苯并噁嗪类化合物的方法,通过该方法合成了一系列新型结构的1-(氨基甲酰基甲基)-2-烃基-3,1-苯并噁嗪类化合物。 对于这类反应BF3·OEt2比三甲基氯硅烷(TMSCl)和四氯化锡(SnCl4)的普适性更广,它能有效催化这类反应,而后二者却不能。 探讨了TMSCl和SnCl4不能催化2-(N-取代氨基甲酰甲基氨基)苯甲醇与醛反应的原因。 相似文献
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以(R)/(S)-4-苄基-2-噁唑烷酮为手性助剂,采用不对称合成方法制备了18个具有光学活性的2-甲氧羰基-4-氟苯基-1,5-苯并硫氮杂卓类化合物9a~9i和14a~14i,经HPLC分析e.e.值较为理想;通过核磁共振谱、红外光谱和高分辨质谱表征了其结构,通过单晶X射线衍射法确定化合物9h的相对构型;用抑菌圈法测试了目标化合物对新生隐球菌的抑菌活性.研究结果表明,由S型手性助剂诱导不对称合成的杂卓对新生隐球菌的抑制作用普遍高于由R型手性助剂诱导合成的杂卓及外消旋体.测试了抑菌活性较好的化合物14a~14f的最小抑菌浓度(MIC)和最小杀菌浓度(MFC),发现其对新生隐球菌的MIC和MFC均低于抗真菌药物氟康唑. 相似文献
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Parsons JG Stachurska-Buczek D Choi N Griffiths PG Huggins DA Krywult BM Marino ST Nguyen T Sheehan CS James IW Bray AM White JM Boyce RS 《Molecules (Basel, Switzerland)》2004,9(6):449-458
The synthesis of (2S)-2-benzyloxymethyl-3-(2-fluoro-4-methoxyphenyl)- propionic acid, (2S)-2-benzyloxymethyl-3-(2-fluoro-4-methylphenyl)propionic acid and (2S)-2-benzyl-oxymethyl-3-(2,4-dimethylphenyl)propionic acid has been achieved by TiCl4 mediated alkylation of the corresponding (4R)-4-benzyl-3-[3-(2-fluoro-4-methoxyphenyl-, 2-fluoro-4-methylphenyl-, 2,4- dimethylphenyl-)propionyl]-2-oxazolidinones, followed by hydrolysis of the chiral auxiliary. The stereochemistry of the alkylation reaction was confirmed by an X-ray crystal structure of (4R)-4-benzyl-3-[(2S)-2-benzyloxymethyl-3-(2- fluoro-4-methylphenyl)propionyl]-2-oxazolidinone. 相似文献
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Suga H Furihata Y Sakamoto A Itoh K Okumura Y Tsuchida T Kakehi A Baba T 《The Journal of organic chemistry》2011,76(18):7377-7387
The catalytic activity of chiral binaphthyldiimine (BINIM)-Ni(II) complexes for asymmetric enantioselective diazoalkane cycloadditions of ethyl diazoacetate with 3-acryloyl-2-oxazolidinone and 2-(2-alkenoyl)-3-pyrazolidinone derivatives was evaluated. The cycloadditions of 3-acryloyl-2-oxazolidinone and its 5,5-dimethyl derivative, in the presence of the BINIM-Ni(II) complex (10 mol %; prepared from (R)-BINIM-4Ph-2QN (ligand C) and Ni(ClO(4))(2)·6H(2)O) afforded 2-pyrazolines having a methine carbon substituted with an oxazolidinonyl group in moderate ratios (70:30 to 72:28), along with high enantioselectivities (90-92% ee) via 1,3-proton migration. On the basis of the investigations on the counteranions of the Ni(II) complex, the N-substituent of pyrazolidinone, and reaction temperatures, the optimal enantioselectivity (97% ee) and ratio (85:15) of 2-pyrazoline were obtained for the reaction of 2-acryloyl-1-benzyl-5,5-dimethyl-3-pyrazolidinone in the presence of (R)-BINIM-4Ph-2QN-Ni(II) ((R)-C/Ni(II)) complex prepared using Ni(BF(4))(2)·6H(2)O. In the cases of 1-benzyl-2-crotonoyl-5,5-dimethyl-3-pyrazolidinone, 1-benzyl-2-(2-butenoyl)-5,5-dimethyl-3-pyrazolidinone, and 1-benzyl-5,5-dimethyl-2-(3-ethoxycarbonyl)propenoyl-3-pyrazolidinone, the use of the (R)-BINIM-2QN-Ni(II) ((R)-A/Ni(II)) complex gave good to high enantioselectivities (85-93% ee) with the sole formation of the 2-pyrazoline having a methine carbon substituted with a pyrazolidinonyl group. Relatively good enantioselectivity (77% ee) was observed for the reaction between 2-acryloyl-5,5-dimethyl-1-naphthylmethyl-3-pyrazolidinone and an α-substituted diazo ester, ethyl 2-diazo-3-phenylpropanoate, which has yet to be employed as a diazo substrate in asymmetric cycloaddition reactions catalyzed by a chiral Lewis acid. 相似文献
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James M. Graham Brock T. Shireman Todd M. Maddux Christina M. Brandstedt Wayne E. Zeller 《合成通讯》2013,43(7):1221-1226
The use of diisopropylcarbodiimide as an agent to effect the coupling of carboxylic acids to Evans' chiral auxiliary (4R, 5S)-4-methyl-5-phenyl-2-oxazolidinone provides the corresponding acyl derivatives in good yields. 相似文献
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Both (4S-(+)-3-(isocyanoacetyl)-4-(phenylmethyl)-2-oxazolidinone (R)-1 and its enantiomer (S)-1 have been synthesized as potentially useful synthons in asymmetric synthesis. Optically active (+)-5-(3,4-dimethoxyphenyl)-4-[[N-[(4S)-2-oxo-4-(phenylmethyl)-2-oxazolidinyl]]carbonyl] oxazole (S)-2 and its enantiomer (R)-2 obtained by treating 3,4-dimethoxybenzoyl chloride with (S)-1 and (R)-1, respectively, in the presence of the nonionic superbase P(MeNCH(2)CH(2))(3)N, have high fluorescence quantum yields. The molecular structure of (S)-2 obtained by X-ray means is also presented. 相似文献
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(4S,5S)-4-Formyl-5-vinyl-2-oxazolidinone (4b), which is readily obtained via a zinc-silver-mediated reductive elimination of alpha-d-lyxofuranosyl phenyl sulfone (3b), is successfully converted to the naturally occurring, nonproteinogenic amino acid (2S,3R)-3-amino-2-hydroxydecanoic acid (2). Also in this study, a facile "oxazolidinone rearrangement" reaction is uncovered during the attempted formation of the (methylthio)thiocarbonate derivative of the oxazolidinone alcohol 7. 相似文献
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同位素稀释质谱法测定蜂蜜中4种硝基呋喃代谢物 总被引:4,自引:0,他引:4
研究了蜂蜜中4种硝基呋喃代谢物:呋喃唑酮代谢物(AOZ)、呋喃它酮代谢物(AMOZ)、呋喃妥因代谢物(AHO)、呋喃西林代谢物(SEM)的同位素稀释HPLC-MS/MS分析方法,以邻硝基苯甲醛作为衍生化试剂,AOZ-d4、AMOZ-d5、AHD-13G3、SEM·HCl-(13C,15 N2)作内标,并将超声波衍生化法应用到实际样品的分析测试当中,以乙腈-0.1%甲酸为流动相,采用梯度洗脱,15 min可将4种代谢物完全分离,再以MS/MS进行定性和定量分析.加标回收率为82%~112%;定量限(LOQ)为0.05~1 μg/kg;检出限(LOD)为0.01~0.25 μg/kg.该方法满足欧盟(EU)对进出口蜂蜜中硝基呋喃代谢物的检测要求. 相似文献