1,4-苯并二(口恶)烷类新木脂素Eusiderin G的全合成

以没食子酸甲酯为原料,经过6步反应(总产率为24％),对 1,4-苯并二噁烷类新木脂素天然产物Eusiderin G进行了全合成。合成反应的关键步骤是在强酸性离子交换树脂催化下,分子内的醇羟基与酚羟基之间发生脱水反应,关环形成1,4-苯并二噁烷骨架化合物。该合成路线具有简便易行、产率较高、副反应少的特点,可适用于其它具有生理活性的1,4-苯二噁烷类化合物的合成。     

1-{8-甲氧基-2,3-二氢苯并[b][1,4]二噁烷-5-基}乙酮的合成

以邻香兰素为起始原料、经氧化裂解、付克反应及环合反应制得PDE-4抑制剂的中间体1-{8-甲氧基-2,3-二氢苯并[b][1,4]二噁烷-5-基}乙酮,总收率58.9%。     

碳酸铯存在下铁催化立体选择性合成(Z)-2-亚基-1,4-苯并二噁烷衍生物

通过Sonogashira偶联反应合成了邻炔丙基醚苯酚衍生物,在Cs2CO3存在和FeCl3的催化下,进而发生分子内环化反应,立体选择性地合成了一系列(Z)-2-亚基-1,4-苯并二噁烷衍生物.产物的结构通过了1H NMR,13C NMR和HRMS等表征.     

苯并二噁唑系列聚合物的合成及表征

以4,6-二氨基-1,3-苯二酚盐酸盐为原料,分别和对苯二甲酸、1,4-萘二甲酸、2,6-萘二甲酸、2,5-噻吩二甲酸、4,4-′(1,2-二苯基乙烯)二甲酸在多聚磷酸介质中反应,合成单环的聚(1,4-亚苯基)苯并二噁唑(PBO)、稠环的聚(1,4-亚萘基)苯并二噁唑(1,4-PNBO)和聚(2,6-亚萘基)苯并二噁唑(2,6-PNBO)、杂环的聚(2,5-亚噻吩基)苯并二噁唑(PTBO)及含有两个苯环的聚-4,4′-亚(1,2-二苯乙烯基)苯并二噁唑(4,4′-PDPEBO).采用傅立叶红外光谱、热重分析、元素分析、特性黏数分析对系列聚合物进行了表征.研究结果表明PBO、1,4-PNBO、4,4-′PDPEBO、2,6-PNBO和PTBO 5种聚合物的耐热性能依次降低,特性黏数依次为25.40、16.76、20.63、15.38和14.63 dL/g.     

2-(ω-联苯基多亚甲基)-5-联苯基噁唑-1,3和2-(ω-联苯基多亚甲基)-5-联苯基噁二唑-1,3,4的合成

继2,6-二取代苯并二噁唑、2,5-二取代噁唑和2,5-二取代噁二唑及1,4-二(苯并噁唑-1,3基-2)苯等系列化合物合成及光性能研究后,又合成了双荧光发色团化合物2-(ω-联苯基多亚甲基)-5-联苯基噁唑-1,3和2-(ω-联苯基多亚甲基)-5-联苯基噁二唑-1,3,4共七种化合物。     

醋酸铜催化“一锅法”合成5-(1-苯基-3-苯基丙基-2-炔基)-2,2-二甲基-1,3-二噁烷-4,6-二酮衍生物

在醋酸铜催化作用下,以抗坏血酸钠为还原剂,以醛、2,2-二甲基-1,3-二噁烷-4,6-二酮和苯乙炔为原料,通过包含Knoevenagel缩合与Conjugate加成反应的多组分反应,有效地合成了10种5-(1-苯基-3-苯基丙基-2-炔基)-2,2-二甲基-1,3-二噁烷-4,6-二酮衍生物.该工艺具有收率高(63%～86%)、反应温和、操作简单及环境友好等优点,为合成5-(3-苯基-1-苯基丙基-2-炔基)-2,2-二甲基-1,3-二噁烷-4,6-二酮衍生物提供了一种有效的方法.     

FTIR监测7-氟-2H-1,4-苯并噁嗪-3(4H)-酮的固相合成

我们已经合成了一系列具有生物活性的杂环取代苯并噁嗪酮类化合物, 为了构建一个苯并噁嗪酮类化合物的组合物库, 我们又探索出了一种固相合成7-氟-2H-1,4-苯并噁嗪-3(4H)-酮的方法, 并用FTIR技术成功地监测、优化了整个反应过程, 并根据得到的红外光谱图对反应动力学进行了探讨.     

2,3-二氢-1,4-苯并噁嗪衍生物的合成研究进展

综述了2,3-二氢-1,4-苯并噁嗪衍生物的合成研究进展,并对其发展趋势、应用前景作了进一步的展望。     

一种新型噁唑烷酮类抗生素的合成

以2,4-二溴吡啶为原料,经Weinreb酰胺酰化、Noyori不对称氢转移反应、脱Boc保护基、环化、Suzuki偶联、磷酸单酯化及成盐共七步反应制得一种新型噁唑烷酮类抗生素【【(3R,3aS)-7-{6-［(S)3-甲基-2-噁唑烷酮-5-基］吡啶-3-基}-1-氧-1,3,3a,4-四氢苯并［b］噁唑［3,4-d］［1,4］噁嗪-3-基】甲基】磷酸单酯二钠盐,其结构经¹H NMR, ¹³C NMR和HR-MS（ESI）确征,总收率7%,纯度99.7%。     

选择性串联合成功能化的苯并[b][1,4]二氮杂?化合物

以取代的邻苯二胺、噻唑-2-甲醛和乙炔二甲酸二乙酯为原料,无水乙醇为溶剂,通过串联反应(亲核加成、脱水、环合和质子转移等)合成了12种新颖的取代的3,4-二乙氧羰基-2-(噻唑-2-基)苯并[b][1,4]二氮杂?化合物.由于化学/区域选择性,在同一反应不同条件下分别得到了烯胺型和亚胺型苯并[b][1,4]二氮杂?的异构体,通过考察反应条件对产物异构体选择性的影响,研究产物选择性的变化规律,为实现选择性合成苯并[b][1,4]二氮杂?化合物提供简便的合成思路.采用密度泛函(DFT)方法在B3LYP/6-31G基组水平上对反应原料和两种目标化合物进行量化计算,从原子布居电荷的角度,进一步对反应的选择性规律进行理论解释,并且在此基础上提出了合理的反应机理.     

Diastereomeric 2-aminomethyl-1,4-benzodioxane mandelates: phase diagrams and resolution

The diastereomeric salts of (R)- and (S)-2-aminomethyl-1,4-benzodioxane with unichiral mandelic acid form a simple eutectic, whose binary phase melting point diagram shows the unique eutectic at 0.35 M ratio of the less soluble diastereomer. Such an eutectic composition, near to 0.5, is consistent with the modest efficiency previously reported for their separation via crystallization from ethanol/ethyl acetate. However, the ternary solubility phase diagram, obtained from solubility measurements in methanol, shifts the eutectic to a lower molar ratio (0.10) of the less soluble diastereomer, thus indicating an optimal resolvability of the diastereomeric mandelates. This was confirmed by the highly efficient resolution of racemic 2-aminomethyl-1,4-benzodioxane with (R)-mandelic acid via a single crystallization from methanol. The ready availability of both the racemic substrate and the resolving acid makes this simple and efficient resolution procedure very attractive to obtain the enantiomers of 2-aminomethyl-1,4-benzodioxane, which are important synthetic intermediates.     

Synthesis of Isoxazole Conjugates of 1,4-Benzodioxane Moiety via Intermolecular 1,3-Dipolar Cycloaddition

1,3-Dipolar cycloaddition was utilized as a tool to conjugate the 1,4-benzodioxane moiety with several biologically active compounds such as steroid, sugar, and other aromatic scaffolds via isoxazole or triazole bridge. The propynyl ether of 2-hydroxymethyl-1,4-benzodioxane underwent 1,3-dipolar cycloadditions smoothly with different in situ generated nitrile oxides in good yields. The triazole conjugate of 1,4-benzodioxane was synthesized via click chemistry.     

A Novel dioxano-annellated benzofuroxan

Oxidation of 6-amino-7-nitro-1,4-benzodioxane using alkaline hypochlorite affords 1,4-benzo-dioxano[6,7-c]furoxan in a very good yield. Pyrolysis of 6-azido-7-nitro-1,4-benzodioxane failed to give the same product. The structure of the new furoxan is confirmed by the spectra.     

Behavior of 6-cyclopropyl- and 6-bromo-7-cyclopropyl-1,4-benzodioxanes under electrophilic substitution reaction conditions

Bromination of 6-cyclopropyl-1,4-benzodioxane occurs with concerted orientation of the ethylenedioxy group and the cyclopropyl radical for the least sterically hindered position of the aromatic ring. Nitration of 6-bromo-7-cyclopropyl-1,4-benzodioxane does not lead to products of substitution of the hydrogen atom in the 5 or 8 position of the 1,4-benzodioxane, but rather to the nitrodebromination product: 7-nitro-6-cyclopropyl-1,4-benzodioxane. The anomalous behavior of the bromo-substituted benzodioxane is explained by the predisposition of the carbon atom bonded to the bromine towardipso attack by an electrophile.M. V. Lomonosov Moscow State University, Moscow 119899. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 618–620, May, 1998.     

(2R，3R)-和(2S，3S)-2-(4-羟基-3-甲氧基)-3-羟甲基-1，4-苯并二氧六环-6-醛的对映选择性合成

1,4-苯并二氧六环木脂素类天然产物多数具有增加胆碱乙酰化酶和抗肝毒等活性 ,其活性主要源于 1 ,4-苯并二氧六环官能团 [1] . 1 ,4-苯并二氧六环木脂素的消旋全合成已有报道 [2 ] ,但其不对称合成还是空白[3] .我们发展了一条对映选择性合成 1 ,4-苯并二氧六环木脂素的简捷有效的路线 .基于前面的工作 [4 ] ,我们发现 1 ,4-苯并二氧六环醛类衍生物是合成此类天然产物的关键中间体 ,选择 2 - (4-羟基- 3-甲氧基 ) - 3-羟甲基 - 1 ,4-苯并二氧六环 - 6-醛 (1 )作为目标分子 ,其合成路线如下 :Reagents and conditions:( ) Me OH,H2 SO4,9…     

Synthesis of new biheterocycles containing a 1,4-benzodioxane fragment

The reaction of 1,4-benzodioxane-2-carbonyl chloride with 5-(4-aminophenyl)-1,3,4-oxa- and -thiadiazole-2-thiols afforded new biheterocyclic compounds which were converted into the corresponding S-benzyl derivatives by treatment with benzyl chloride. 5-(4-Aroylaminophenyl)-1,3,4-oxa(thia)diazole-2-thiols reacted with 2-bromomethyl-1,4-benzodioxane to give compounds in which the 1,4-benzodioxane nucleus and fivemembered heterocycle are linked through a CH₂S bridge.     

First Enantioselective Synthesis of (2R,3R)-and(2S,3S)-2-(4-hydroxyphenyl)-3-hydroxymethyl-1,4-benzodioxan-6-carbaldehyde

Numerous lignans containing 1,4-benzodioxane nucleus represent a class of natural products with cytotoxic and hepatoprotective activities1,2. Recently we have reported the racemic total synthesis of sinaiticin, a flavonolignan of the 1,4-benzodioxane type which was isolated from sinaiticum leaves found in sinai region of Egypt, using 2-(4-hydroxyphenyl)-3-hydroxymethyl-1,4-benzodioxan-6-carbaldehyde as the key interme-diate3,4. This species exhibits significant inhibitory activity against the …     

Synthesis and biologic properties of new thiazolylbenzodioxane derivatives

Reaction of 4-(1,4-benzodioxan-2-yl)thiazol-2-amine with acid chlorides afforded N-substituted amides which further were reduced into the corresponding amines. A new method was developed of preparation of 2-acetyl-1,4-benzodioxane, the initial compound in the synthesis of thiazolylbenzodioxane and numerous derivatives of this series. The adreno- and sympatholytic as well as antihypoxic effect of the obtained biheterocyclic 1,4-benzodioxane derivatives were investigated.     

Synthetic analogs of naturally occurring flavolignans. XI. Reaction of synthetic flavone analogs with hydrazine hydrate and its derivatives

Reactions of 1,3-benzodioxane and 1,4-benzodioxane analogs of flavones with hydrazine derivatives are studied. The hydrazines recyclize the new flavones into 3,5-diarylpyrazoles. Their PMR spectra confirm their structures.Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 40–41, January–February, 2000.