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1.
1INTRODUCTIONManypyrazolederivativeshavebeenreportedtoshowvariousbiologicalactivitiestobeusedasbactericide[1],fungicide[2],herbicide[3],insecticide[4]andvirucide[5]agents.Inaddition,4-thiazolidinoneplaysavitalroleowingtoitswiderangeofbiologi-calactivities…  相似文献   

2.
1INTRODUCTIONPolarizedketenedithioacetalshavebeenex-tensivelyusedasbuildingblocksinorganicsyn-thesis,especiallyinthesynthesisofheterocycliccompounds[1~6].Pyrazoleanditsderivativesrepre-sentoneofthemostactiveclassesofcompoundspossessingwidespectraofbiologicalactivities.Overthepastfewyears,considerableevidenceshavebeenaccumulatedtodemonstratetheefficacyofpyrazolederivatives,suchasantibacterial[7],fun-gicidal[8],herbicidal[9],insecticidal[10]andotherbiologicalactivities[11,12].Uptonow,alarg…  相似文献   

3.
Introduction Chiralsecondaryalcoholsareveryimportantinter mediatesinorganicsynthesis.Theyaregenerallypre paredviachemicalorenzymaticresolutionofracemic secondaryalcohols[1—4],chemicalorenzymaticasym metricreductionofprochiralketones[5—7],andasym metrica…  相似文献   

4.
1INTRODUCTIONThepyrazolo[3,4-b]pyridineclassofcompoundspossessmanybiologicalandpharmacologicalactivi-ties[1],suchasactiveanti-concretionmedicaments[2]aswellasactiveanti-gramnegativeandpositivebacteriaagents[3].Thereforethesynthesesofsuchcompoundshavearousedgreatattentionofalargenumberofchemists.Themostimportantsyntheticrouteisthecondensationreaction[4~11]ofamino-pyrazoleandα,β-unsaturatedcompounds.Theorganicreactionundermicrowaveirradia-tionhastheadvantagesoffastreactionspeed,shorttime…  相似文献   

5.
化合物3-甲基-2-戊烯-4-炔-1-醛两端均为活性官能团,在分子连接及成环反应中能够起到非常重要的作用,是合成轮烯酮[1-7],脱落酸[8]和二苯基二苯并环辛烯[9]等的重要中间体.  相似文献   

6.
4甲基4′氨基二苯醚是合成农药、染(颜)料、医药的重要中间体.传统的制备方法是由4 甲基4′硝基化合物(简称硝基物)在盐酸存在下用二氯化锡还原得到[1] ,该方法工艺成熟、产品质量好,但产率低,污染严重.陈其亮等报道了由硝基物催化加氢的方法[2],但存在设备投资大,操作繁锁等缺点.二氧化硫脲(Thiourea dioxide ,简称TD)是一种非常优良的还原剂,已广泛应用于有机合成的许多方面[3,4],但应用于标题化合物的制备未见报道,本文对此进行了研究,收到较好效果.合成路线如下:  相似文献   

7.
1 INTRODUCTION The pyrazolo[3,4-b]pyridine system has many interesting biological and pharmacological proper- ties, such as active antitubercular agents[1, 2], active agents against gram positive and negative bacteria[3], ACTH(Adrenocorticotropic hormone…  相似文献   

8.
1 INTRODUCTION Since the discovery of pharmacological effectsof 1,4-dihydropyridine (1,4-DHPs) as calcium mo-dulators[1], a great deal of work has been directedtowards the synthesis of 1,4-DHPs acting as cal-cium antagonists[2]. The chemical modifications onthe DHP ring, such as the introduction of differentsubstituents on heteroatoms[3], have allowed theexpansion of researches on structure-activity rela-tionship to have new insight into the molecularinteractions at the receptor l…  相似文献   

9.
三唑类衍生物是重要的化工和药物合成中间体,而稠合三唑类衍生物因其独特的生理活性更是得到了广泛关注[1-2],其中3-三氟甲基-5,6,7,8-四氢[1,2,4]三唑并[4,3-α]哌嗪与β-氨基酸缩合得到的化合物是一类重要的二肽基肽酶-Ⅳ抑制剂 [3-4],可作为2型糖尿病的治疗药物,如2006年经美国FDA批准在美国上市的西他列汀(sitagliptin),此外二肽基肽酶-Ⅳ抑制剂还可用于肥胖症和高血压等疾病的预防和治疗[5].  相似文献   

10.
1 INTRODUCTION The molecular assembly of one- or multi-dimen-sional aggregation by hydrogen bonds is now an im-portant subject of supramolecular chemistry and crys-tal engineering[1, . Supramolecular structures formed 2]via intermolecular hydrogen bonds X–H…X or C–H…X (X = O, Cl, N, et al.) are very common inorganic compounds[3~12], and they generally possessdifferent properties due to these hydrogen bonds. Concerning about the spectra of benzene-contai-ning…  相似文献   

11.
用KBH_4,CaCl_2为还原剂使D及L缬氨酸甲酯还原得到光学活性产物R-3-甲基-2-氨基丁醇(2a)及S-3-甲基-2-氨基丁醇(2b)。2a,2b同CS_2在KOH存在下反应得到(R)-4-异丙基四氢噻唑-2-硫酮(3a)及(S)-4-异丙基四氢噻唑-2-硫酮(3b)。肉桂酰氯分别同3a及3b在Et_3N存在下反应得到N-肉桂酰(R)-4-异丙基四氢噻唑-2-硫酮(4a)及N-肉桂酰(S)-4-异丙基四氢噻唑-2-硫酮(4b)。用半经验的量子化学PM3方法研究了反应物和产物的电子结构,得到了产物的最优构型和电荷键序分布以及反应焓变。  相似文献   

12.
The preparation of the diastereomerically pure beta-tetralone ketal 4 is reported. Intramolecular alkylidene C-H insertion followed by hydrolysis of 4 proceeded to give the enantiomerically pure cyclopentene 15. The key step in this synthesis was the bis-intramolecular cyclization of keto aldehyde 2 to give the tetracyclic intermediate 20. Enone 20 was converted over several steps to (-)-morphine 1.  相似文献   

13.
The crystal structure of the new title compound 3-(4-chlorophenyl)-8-cyano-2-(di-iso-propylamino)-5-methyl-7-(methylthio)-pyrido[4,3-d]pyrimidine-4(3H)-one(C22H24ClN5OS,Mr = 441.97)has been determined by single-crystal X-ray diffraction. The crystal is of orthorhombic,space group Pna21 with a = 7.6721(5),b = 18.9370(11),c = 15.6260(9),V = 2270.2(2)3,Z = 4,Dc = 1.293 g/cm3,F(000)= 928,μ = 0.283 mm-1,MoKa radiation(λ = 0.71073 ),R = 0.0494 and wR = 0.1062 for 3278 observed reflections with I > 2σ(I). X-ray diffraction analysis reveals that all ring atoms in the py-ridopyrimidinone moiety are almost coplanar. Intramolecular C(20)-H(20)···N(4),C(19)-H(19A)···N(3),C(18)-H(18C)···N(3)and C(16)-H(16B)···O(5)hydrogen bonds together with weak C···π interactions are found in the structure.  相似文献   

14.
1 INTRODUCTION Recently, for the fluorescent properties, Schiff base has been more and more important and widely studied in density optical memories, nonlinear op- tics (NLO), organic light-emitting diodes (OLED), polymer LED and electrogenerated chemilumines- cence (ECL)[1~5]. Thiosemicarbazones are a kind of Schiff bases with thiourea and good ligands easily chelating with transition metal ions. Although they have been studied extensively for a long time due to their chemical and b…  相似文献   

15.
1INThODUCT1ONInaprevi0uspaPer"',wereP0rtedthesyntheses0fsome1,3,4-diazaphospho-lidin-2-thione-4-oxidesandtheirhighselectiveherbicidalactivity.Althoughtherewereseveralreportsaboutthedesulphurisationofsomestraightchainthioureaderiva-tivest2'31,uptonow,thedesulphurisationreactionofcyclicthioureaderivativesutiliz-ingAgNO,-H,Osystemhasnotbeenstudied.InthispaPer,thedesulphurisation0fcis-3,4-diphenyl-5-(2,4-dichlorophenyl)-1,3,4-diazaphOSpholidin-2-thione-4-oasthecyclicsubstrateisrep0rtedfort…  相似文献   

16.
An alternate synthesis of 1-(2,4-dichlorophenyl)-4-(2-imidazolyl)-1-butanones 5d is presented after 1-[(dimethylamino)methyl- and 1-methyl]-2-lithioimidazole failed to be substituted satisfactorily by 2-(2,4-dichlorophenyl)-2-(3-iodopropyl)-1,3-dioxolane ( 3b ). The Pinner addition of ethanol to 2-(2,4-dichlorophenyl)-2-(3-cyanopropyl)-1,3-dioxolane yielded the corresponding imidate which was reacted with 1-amino-2,2-dimethoxyethane to form an amidine. Hot dilute hydrochloric acid converted this ami-dine to the 2-imidazolyl ketone 5b . Syntheses of homologous 1-(4-chloro- and 2,4-dichlorophenyl)-4-(2-imidazolyl)-1-pentanones 20 are described. Ketalizations of 5 and 20 with glycerol formed imidazolyl 1,3-dioxolanyl alcohols. Selective N- and O-alkylations of some of these imidazolyl alcohols are described.  相似文献   

17.
The title compound, 4-amino-3-(p-chlorophenyl)-5-(p-methoxybenzyl)-4H-1,2,4- triazole I , C16H15ClN4O), has been determined using X-ray diffraction techniques and the molecular structure has also been optimized at the B3LYP/6-31 G(d, p) level using density functional theory (DFT). The triazole ring exhibits dihedral angles of 41.61(15)o and 80.73(11)o with the phenyl rings. The molecules are linked principally by N–H…N hydrogen bonds involving the amino NH2 group and a triazole N atom, forming C(5) chains which are further linked to give a two-dimensional network of molecules. The N–H…N hydrogen bonding is supported by C–H…N hydrogen bond and C–H…π interaction. Intermolecular N–H…N and C–H…N hydrogen bonds produce R22(9), R44(10) and R44(20) rings.  相似文献   

18.
1 INTRODUCTION3methyl4hydroxybenzofuranisanintermediateusedforthesynthesisofnatureproducts[1].Ithasbeensynthesizedfrom1,3dihydroxybenzene[2-3].Tosynthesizeabietanequinonediterpenoidswithit[4,5],weintendedtoprotectthehydroxyattachedtoitwithMe2SO4.Finally,twocompou…  相似文献   

19.
Pugh C 《Organic letters》2000,2(9):1329-1331
[formula: see text] NaBH4 reduction of 2,5-bis[(4'-(n-alkoxy)benzoyl)oxy]benzaldehydes produces primarily the rearranged phenol, which does not generate liquid crystalline phases when laterally attached to a polymer backbone. Rearrangement is prevented by quenching the intermediate benzyl alkoxide with a weak acid. For example, 2,5-bis[(4'-(methoxy)benzoyl)oxy]benzaldehyde is selectively reduced to 2,5-bis[(4'-(methoxy)benzoyl)oxy]-benzyl alcohol with less than 5% intramolecular transesterification using 2-3 equiv of NaBH4 in the presence of 20-30 equiv of acetic acid (1:10 NaBH4/AcOH).  相似文献   

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