9,9-二甲基-2-(4-甲氧基苯基)-4-苯基-9H-吡啶并[1,2-a]吲哚高氯酸盐的微波合成及晶体结构

利用2,3,3-三甲基-3H-吲哚高氯酸盐、1-苯基-3-(4-甲氧基苯基)-2-丙烯-1-酮与哌啶在微波辐射条件下合成了9,9-二甲基-2-(4-甲氧基苯基)-4-苯基-9H-吡啶并[1,2-a]吲哚高氯酸盐, 在甲醇中培养出单晶, 通过X射线单晶结构分析法测定分子结构和晶体结构, 晶体属于正交晶系, Pca2₁空间群, 晶胞参数为: a＝2.7923(6) nm, b＝0.92126(17) nm, c＝1.8345(4) nm, V＝4.7190(16) nm³, D_c＝1.345 g/cm³, μ＝0.201 mm^－1, F(000)＝2000, Z＝8, R₁＝0.0566, wR₂＝0.1320.     

3-对甲氧基苯基-和3-对羟基苯基-1-氨基-3a,4,5,9b-四氢化-9b-羟基-3H-环戊烯并[a]萘-2-甲腈的合成和晶体结构

用低价钛试剂(TiCl₄-Zn)与2-氰基-3-对甲氧基苯基-3-(1-四氢萘酮-2-基)丙腈反应合成了3-对甲氧基苯基-1-氨 基-3a,4,5,9b-四氢化-9b-羟基-3H-环戊烯并[a]萘-2-甲腈和3-对羟基苯基-1-氨基-3a,4,5,9b-四氢化-9b-羟基-3H-环戊烯并[a]萘-2-甲腈, 并用X射线衍射分析确定了这两个产物的结构.     

2',4"-O-双(三甲基硅)红霉素A 9-O-(1-乙氧基-1-甲基乙基)肟的区域选择性甲基化

一锅煮合成并表征了2',4"-O-双(三甲基硅)红霉素A 9-O-(1-乙氧基-1-甲基乙基)肟, 首次在丙酮-水混合溶剂中培养出了单晶. X射线衍射表明, 其结构为四方晶系, I4空间群, 晶胞参数: a＝b＝2.9536(1) nm, c＝1.4488(1) nm, V＝12.63897(4) nm³, Z＝8, R＝0.068, wR＝0.067. 对区域选择性影响因素的研究表明: 甲基化时溶液浓度应控制0.052 mol/L和0.067 mol/L之间; 分别采用了四氢呋喃、二氯甲烷、甲基叔丁基醚、甲苯与二甲亚砜作为混合溶剂进行甲基化反应, 发现在甲苯-二甲亚砜中的效果最好, 6-OH的甲基化选择性可达到81.69%.     

1,3-偶极环加成合成新型3a,6a-二氢-4,6-二氧代吡咯啉并[3,4-d]吡唑类衍生物

α-氯代-4-氧代-4H-1-苯并吡喃-3-甲醛芳腙与N-取代苯基-马来酰亚胺在三乙胺作用下通过1,3-偶极环加成合成了一系列含3-(4-氧代-4H-1-苯并吡喃-3-基)-3a,6a-二氢-4,6-二氧代吡咯啉并[3,4-d]吡唑类衍生物. 化合物结构经元素分析, IR, ¹H NMR及MS确证.     

N-烷基/芳基-N'-(4-芳基噻唑-2-基)-N"-糖基胍的合成及生物活性研究

2,3,4,6-四-O-乙酰基-β-D-吡喃葡萄糖基异硫氰酸酯(1)与2-氨基-4-取代苯基噻唑(2a～2b)反应, 生成糖基硫脲衍生物3a～3b, 再在伯胺存在下经氯化汞脱硫, 得到一系列新的N-烷基/芳基-N'-(4-芳基噻唑-2-基)-N"-糖基胍类化合物(4a～4e, 5a～5e). 所有新化合物的结构均经IR, ¹H NMR, MS谱和元素分析证实, 所得产物均为β-构型. 生物活性测试结果表明, 化合物4b和5d对HIV-1 PR表现出了较高的抑制活性.     

新型1,2,4-三唑[3,4-b]-1,3,4-噻二嗪的合成及表征

以3-(2-苯基-1,2,3-三唑-4-基)-4-氨基-5-巯基-1,2,4-三唑(1)为原料分别与ω-溴代芳基乙酮、ω-溴代-ω-(1H-1,2,4-三 唑-1-基)芳基乙酮反应, 合成了一系列新的1,2,4-三唑[3,4-b]-1,3,4-噻二嗪类化合物2a～2e和3a～3e. 其结构经IR, ¹H NMR和MS及元素分析确证.     

D-谷氨酰胺的制备

报道了以化学合成和生物转化的方法制备光学纯D-谷氨酰胺. 首先在中试规模上用化学方法合成DL-谷氨酰胺. 即以廉价的DL-谷氨酸为原料, 采用邻苯二甲酰基作为保护基保护L-谷氨酸的α-氨基, 醋酐回流15 min, 使其分子内脱水生成N-邻苯二甲酰-DL-谷氨酸酐, 在常温、常压条件下, 分别与2 mol/L氨水反应生成中间产物N-邻苯二甲酰-DL-谷氨酰胺, 中间产物在室温条件下与0.5 mol/L水合肼反应48 h脱除保护基, 以57%总收率得到DL-谷氨酰胺. 在37 ℃, pH 4.8的条件下, 利用大肠杆菌(E. coli. AS 1.505)脱羧酶将底物浓度30 g/L的DL-谷氨酰胺中L型对映体在8 h内完全转化为4-氨基丁酰胺, 分离得到D-谷氨酰胺.     

N,N'-二茂铁甲基-(1S,2S)-1,2-二苯基乙二胺的合成及其在烯烃的不对称双羟基化反应中的应用

(1S,2S)-1,2-二苯基乙二胺和甲酰基二茂铁经缩合和还原两步反应, 以90%的产率合成了N,N'-二茂铁甲基-(1S,2S)-1,2-二苯基乙二胺, 并以其为配体催化烯烃的不对称双羟基化反应, 获得了较高的对映选择性(71%～86% ee).     

7-取代苯氧基-4,5-二氢-1,2,4-三唑并[4,3-a]喹啉和喹啉-1(2H)-酮衍生物的合成及抗惊厥活性

合成了7-取代苯氧基-4,5-二氢-1,2,4-三唑并[4,3-a]喹啉(3a～3g)和7-取代苯氧基-4,5-二氢-1,2,4-三唑并[4,3-a]喹表明啉-1(2H)-酮(4a～4g)类衍生物. 以最大电惊厥法和戊四唑法测定了抗惊厥活性, 以旋转棒法测定了神经毒性. 结果表明, 化合物7-(4-氟苯氧基)-4,5-二氢-1,2,4-三唑并[4,3-a]喹啉-1(2H)-酮(4c)显示最强的抗惊厥作用和低的神经毒性, 其抗电惊厥ED₅₀为6.8 mg/kg, 神经毒性TD₅₀为88.0 mg/kg, 保护指数PI为12.9, 明显优于对照药苯妥英钠.     

水相中2-氨基-4-芳基-5,6-二氢化-4H-吡喃并[3,2-c]喹啉-5-酮衍生物的合成

以芳亚甲基丙二腈或2-氰基-3-芳基丙烯酸酯和4-羟基喹啉-2-酮为原料, 水为溶剂, 在TEBA(三乙基苄基氯化铵)催化下90 ℃, 合成了2-氨基-4-芳基-5,6-二氢化-4H-吡喃[3,2-c]喹啉-5-酮衍生物. 和其它方法相比, 该反应具有反应条件温和, 产率高(87%～96%)和环境友好等优点. 产物的结构通过熔点, IR, ¹H NMR和元素分析表征. 化合物3m的结构通过X单晶衍射分析确证.     

A Facile and Efficient Synthesis of Novel 1,2,4-Triazolo[5,1- b ]quinazolin-9-one Derivatives

 A facile and efficient synthesis of a series of novel 1,2,4-triazolo[5,1-b]quinazolines is described. 2,3-Diaryl-2,3-dihydro-1H-1,2,4-triazolo[5,1-b]quinazolin-9-ones were obtained by reaction of 3-amino-2-arylamino-3H-quinazolin-4-ones with aromatic aldehydes as well as by ring closure of the corresponding anils. Treatment of 3-amino-2-arylamino-3H-quinazolin-4-ones with aromatic carboxylic acids afforded 2,3-diaryl-3H-1,2,4-triazolo[5,1-b]quinazolin-9-ones which could also be synthesized by dehydrogenation of the corresponding dihydro derivatives. Reaction of 3-amino-2-arylamino-3H-quinazolin-4-ones with diethyl malonate and acetylacetone gave 3-aryl-3,9-dihydro-9-oxo-1,2,4-triazolo[5,1-b]quinazolin-2-yl-acetic acid ethyl ester and 3-aryl-2-methyl-3H-1,2,4-triazolo[5,1-b]quinazolin-9-ones, respectively. The latter compounds were also prepared via reaction with acetic anhydride, whereas acetylation with acetic anhydride in the presence of pyridine afforded the acetyl derivatives.     

Synthesis of the Janus integer pheromone (4R,9Z)-9-octadecen-4-olide

The synthesis of (4R,9Z)-9-octadecen-4-olide 1, the female sex pheromone of Janus integer is reported using a Zipper isomerization reaction as the key step.     

Syntheses and regiochemistry of enol addition to 9-phenyl-9H-xanthen-9-ol

Regioselective C-C bond formation of 9-phenyl-9H-xanthen-9-ol 1 with various enolizable ketones I-X in an acidic (HBr) medium, obtained by the reaction of 1,1′-(ethane-1,2-diyl)dipyridinium bistribromide (EDPBT) with ketone is observed. Except for ketone, 4-methyl-pentan-2-one VII in all other cases examined the attack to xanthenyl carbocation is from the thermodynamically stable enolizable side of the unsymmetrical ketones. In the case of 3-methyl-butan-2-one VIII the equilibrium is in favor of the more stable enolizable ketone, which has large steric factor, hence no reaction was observed during its addition to alcohol 1.     

B-frame supported bimetallics. [(PMe2ph)2PtB9H11Ru(η-PrC6H4Me)] and [(PMe2ph)2PtB9H9Ru(η-PrC6H4Me)]; an interesting pair of electron-deficient nido and closo geometries

[7,7-(PMe₂Ph)₂-9-(η⁶-^isoPrC₆H₄Me)-7,9-PtRuB₉H₁₁] has a formal closo Wadian cluster-electron count, but a nido geometry, whereas [1-(η⁶-^isoPrC₆H₄Me)-4,4-(PMe₂Ph)₂-1-4-RuPtB₉H₉], which does have a closo geometry, has a formal sub-closo cluster electron count; both compounds are formed in the reaction between [6-(η⁶-^isoPrC₆H₄Me)-nido-6 RuB₉H₁₃], KH and [PtCl₂(PMe₂Ph)₂].     

Synthesis of 4-Methyl-2,6-di(9H-thioxanthen-9-yl)aniline

Russian Journal of Organic Chemistry - 4-Methyl-2,6-di(9H-thioxanthen-9-yl)aniline was synthesized by the reaction of 4-methylaniline with N-thioxanthenylpyridinium perchlorate in a 1: 3 ratio at...     

Diastereoselective synthesis of 3,4-disubstituted 5-(p-tolylsulfinyl)-5,6-dehydropiperidin-2-ones: chirality transfer in the enantioselective synthesis of ethyl (+)-(3S,4aS,7aS)-1-oxo-octahydro-1H-cyclopenta[c]pyridine-3-carboxylate

The base-mediated reaction of enantiomerically pure -sulfinylketimine (+)-1 with (E)-,β-disubstituted propenoate esters afforded 3,4-disubstituted-5-(p-tolylsulfinyl)-5,6-dehydropiperidin-2-ones 9-13 and 14 with high or complete diastereoselectivity. A sole diastereomer of the four possible ones, with regard to the nature of ester, was isolated, which revealed the stereocontrol of the chiral sulfinyl group in the Michael reaction and transenolization steps. In addition, the enantioselective synthesis of ethyl (+)-(3S,4aS,7aS)-1-oxo-octahydro-1H-cyclopenta[c]pyridine-3-carboxylates (+)-17 is described (five steps; 47% yield; ee 97%). The absolute configuration of stereocentres introduced in (+)-17 was assigned on the basis of ¹H NMR data.     

Synthesis of regioisomeric difluoro- and 8-chloro-9- fluorobenz [g] isoquinoline-5,10-diones and SNAr displacements studies by diamines: bis(aminoalkyl)aminobenz[g] isoquinoline-5,10-diones

Convenient pathways have been developed for the synthesis of 6,7−, 6,8-, 7,9- and 8,9-difluorobenz[g] isoquinoline-5,10-diones and 8-chloro-9-fluorobenz [g] isoquinoline-5,10-dione. The crucial step in these synthesis involved the Ni-catalyzed coupling of the difluoro- or chlorofluorobenzylic zinc bromides with ethyl 3-chloroisonicotinate or ethyl 4-chloronicotinate. The reactions of the 6,7- or 8,9-difluoro regioisomers with N,N-dimethylethylenediamine led to quaternary salts which were formed by intramolecular displacements from the initial mono displacement products. These cyclizations could be obviated with the use of 3-dimethylaminopropylamine in the displacements which led to the desired bis (aminoalkyl) amino substitution products. Treatment of 8-chloro-9-fluorobenz [g] isoquinoline-5,10-dione with N,N-dimethylethylenediamine led to the regioselective displacement of fluoride. Treatment of this mono substitution product with excess N,N-dimethylethylenediamine led only to the intramolecular cyclization product which was also obtained by reaction of 8,9-difluorobenz[g] isoquinoline-9,10-dione with N,N-dimethylethylenediamine. The 6,8- and 7,9-difluoro analogues on treatment with N,N-dimethylethylenediamine or 3-dimethylaminopropylamine led to the expected bis substitution products.     

Ab initio study of atropisomers of derivatives of 1,8-di-pyridine 9H-fluorene, dibenzo[b,d]furan, 9H-carbazole and dibenzo[b,d]thiophene

Ab initio calculation at HF/6-31G^* and MP2/6-31G^* levels of theory for geometry optimization of some syn- and anti-1,8-di-pyridine 9H-fluorene, dibenzo[b,d]furan, 9H-carbazole and Dibenzo[b,d]thiophene are reported. The rotational barrier energy, heat of formation and Gibbs energy are determined for the conversion of the anti-(syn) to the syn (anti)-isomers at 25 °C in the gas phase. The models are chosen as isomers of 9H-fluorene, dibenzo[b,d]furan, 9H-carbazole and dibenzo[b,d]thiophene as scaffold with pyridine as module. Results obtained show that (at equilibrium) for most of atropisomers the syn- is favored over the anti-isomer. Moreover, the ground state structures show that the modules are not parallel to each other but are tilted away in order to increase separation and there by minimize electrostatic repulsion. In atropisomers of 9H-carbazole the isomers are showing an attraction due to the presence of nitrogen atom. Influence of the position of nitrogen atom on the magnitude of the rotational barriers in these atropisomers is also studied.     

The Synthesis and Chemistry of 9-Chlorobicyclo[6.1.0]Non-1(9)-Ene

9-Chlorobicyclo[6.1.0]non-l(9)-ene ( 4 ), a 2-chlorinated 1,3-fused cyclopropene, is synthesized and isolated from the dehalogenation of the l-bromo-9,9-dichlorobicyclo[6.1.0]nonane, itself derived from cyclooctene. Compound 4 undergoes ring opening reaction to generate cyclooctenyl chlorocarbene ( 9 ) which reacts with water via conjugate addition and ipso-addition to give ( E )-2-(chloromethylene)cyclooctanol ( 7 ) and cyclooctene-l-carboxaldehyde ( 8 ), respectively. The conjugate addition of 9 with water is more favorable than the ipso-addition by 3:1. Compound 4 , which is stable at ?25 °C for weeks without any decomposition, reacts with oxygen to produce 2-chlorocyclonon-2-enone ( 12 ) via the ring-opening reaction adduct, vinyl alkylcarbene 10 .