- Mild hydrolysis or alcoholysis of amides. Ti(IV) catalyzed conversion of primary carboxamides to carboxylic acids or esters
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Reaction of primary amides (e.g., 1a or 6-13) or O-methylhydroxamates (1b and 1c) with a catalytic amount of TiCI4 and one equivalent of aqueous HCI converts these compounds in good yields to carboxylic esters (when an alcohol is used as solvent) or to carboxylic acids (when 9:1 dioxane:H2O is used as solvent). These conversions are chemoselective for primary amides: mono- and dialkyl amides are not affected by the reaction conditions. The hydrolysis conditions described do not compromise the stereochemical integrity of an adjacent chiral center. This is exemplified by the hydrolysis of naproxen amide (34) to naproxen (33) without detectable racemization as determined by chiral HPLC.
- Fisher,Caroon,Stabler,Lundberg,Zaidi,Sorensen,Sparacino,Muchowski
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- Dependence of Liquid-Crystal Behavior of a Substance on Molecular Structure
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A novel azoester homologous series of liquid crystals (LCs) consisting of 12 members has been synthesized and evaluated. All members of the series exhibit the nematic mesophase enantiotropically without the exhibition of a smectic mesophase. The textures of the nematic phase are threaded or Schlieren in type. The transition curves in the phase diagram behave in a normal manner. The N-I transition curves exhibit an odd-even effect. The analytical and spectral data support the molecular structures of the homologs. The transition temperatures and mesophase morphology were determined by an optical polarizing microscope equipped with a heating stage. The azoester compounds consist of three phenyl rings with a meta substituted -Cl group at the middle phenyl ring and -OR and -OCH3 as terminal end groups. The average nematic thermal stability is 195°C and the nematogenic mesophase length ranges from 9°C to 186°C. The LC behaviors of the series are compared with a structurally similar series. The novel series is entirely nematogenic and of a high melting point type.
- Makwana,Doshi
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- Mesomorphism dependence on positional substitution of same polar group on same phenyl ring in isomeric homologous series
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Novel homologous series 4-(4′-n-alkoxy benzoyloxy) napthyl azo 2″ - nitro benzenes, consisted of eleven members of a series. All the eleven members (methoxy to tetradecyloxy) homologs are only enantiotropically nematogenic without exhibition of any smectogenic character. Transition temperatures and the textures are determined by an optical polarizing microscopy equipped with a heating stage. Textures of a nematic phase are threaded or schlieren. Analytical and spectral data supported the molecular structure of homologs. Transition curves viz., solid-nematic and nematic-isotropic showing phase behavior of the mesophase in a phase diagram behave in normal manner. Odd-even effect and alternation of transition temperatures are exhibited by N-I transition curve. N-I thermal stability is 129.7°C and Nematic mesophase vary from 12 to 64°C. Thus, novel series is entirely nematogenic and middle ordered melting type. Mesomorphic behavior of a novel series are compared with the structurally similar homologous series.
- Prajapati,Doshi
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- Synthesis and study of novel liquid crystalline homologous series: 4-(4′- n -alkoxy benzoyloxy)-3-methoxy phenyl azo-3″, 4″ dichlorobenzenes
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The synthesis and mesomorphic properties of a new homologous series of azomesogens, 4-(4′-n-alkoxy benzoyloxy)-3-methoxy phenyl azo-3″,4″ dichlorobenzene is detailed. The first four members of the series are nonmesomorphic, and the other eight members are smectogenic in character. The smectic mesophase, which is exhibited montropically, commences from the pentyl to the hexadecyl derivatives. The usual odd-even effect is observed in the isotropic-smectic transition curve. The isotropic-smectic transition curve behaves in a normal manner. The smectic mesophase shows a focal conic fan shaped texture of the smectic A type. An important feature of the series is the absence of the nematic property. The thermal stability and mesomorphic characteristic are compared with two structurally similar homologous series.
- Chauhan,Doshi, Ankita A.,Doshi
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- Facile synthesis of acacetin-7-O-β-d-galactopyranoside
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Acacetin-7-O-β-d-galactopyranoside (1), a natural flavonoid isolated from flower heads of Chrysanthemum morifolium, has been reported to inhibit the replication of HIV in H9 cells. We achieved the total synthesis of compound 1 by employing a one-pot synthesis of the aglycon. The key reactions in this approach include the modified Baker-Venkataraman reaction and regio- and stereoselective O-glycosylations.
- Zacharia, James T.,Hayashi, Masahiko
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- 1-Phenacylmethyl-2-(acylaminothiocarbonylamino)pyridinium bromides as protectors of steel acid corrosion
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Inhibiting effect of 1-phenacylmethylpyridinium bromides containing acylthiourea substituents in the pyridine ring on corrosion of mild steel in sulfuric acid (3 M) was studied.
- Yurchenko,Pogrebova,Pilipenko
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- Mesomorphism dependence on molecular flexibility
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A novel ester homologous series of liquid crystals with a highly polar laterally substituted –OCH3 group is synthesized and studied with a view to understanding and establishing the effects of molecular structure involving lateral substitution on liquid crystal behavior. The novel series RO·C6H4·COO·C6H3·OCH3(ortho)CH=CH·COO·C2H5 consists of 12 homologs of which C7, C8, C10 are nematogenic and C12, C14, C16 homologs are smectogenic. The rest of the homologs are nonliquid crystals. The textures of nematic phase are threaded and the smectic phase is of the type A or C. Transition temperatures and the textures of mesophases were determined by an optical polarizing microscope equipped with a heating stage. Analytical and spectral data support the molecular structures. The N-I and Sm-I transition curves behave in normal manner without exhibition of an odd-even effect. Average thermal stability for smectic and nematic are 127.3°C and 129°C, respectively. The total mesophase length ranges from 17°C to 57°C and series is of a middle ordered melting type with transition temperatures varying between 82°C and 148°C. The liquid crystal properties of present novel series are compared with, structurally similar known homologous series.
- Travadi,Vadodaria,Ladva,Doshi
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- An unexpected and green synthetic protocol for ethyl 1-aroyl/aroylmethyl-5- methyl-3-methylthiopyrazole-4-carboxylates: High regioselectivity in alkylation and acylation reactions between n-1 and n-2 of a pyrazole ring
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Two series, totaling twelve, of new compounds, ethyl 1-aroyl/(aroylmethyl)- 5-methyl-3-methylthiopyrazole-4-carboxylates (5/6), have been synthesized via highly regioselectively acylation and alkylation reactions of ethyl 3-methyl-5-methylthio-1H-pyrazole
- Wen, Li-Rong,Wang, Shu-Wen,Li, Ming,Qi, Wen-Ying,Zhang, Xiu-Li,Yang, Hua-Zheng
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- The synthesis and mesomorphic properties of a novel homologous series: α-4-[4′-n-alkoxy benzoyloxy] benzoyl-β-2″-nitro phenyl ethylenes
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The synthesis and mesomorphic properties of novel homologous series are reported. All 11 members of the series, except the methoxy and ethoxy derivatives, are enantiotropically mesogenic. The propoxy to tetradecyloxy homologues exhibits smectognic amd nematogenic behavior, while the hexadecyloxy homologue shows only nematogenic behavior. An odd-even effect is observed for the smectic-nematic and the nematic-isotropic transition curve in the phase diagram. Analytical data support the structure of molecules. The textures of the nematic mesophase are threaded or Schlieren, and that of smectic mesophase are of type-A. The transition temperatures of homologues and other mesomorphic properties are determined using optical polarizing microscopy. The smectic and nematic thermal stabilities are 138.0°C and 163.8°C respectively. The novel series is predominantly nematogenic and partly smectogenic with middle-ordered melting type. The nematic and smectic phase ranges vary between 16°C and 38°C and 6°C and 22°C respectively. The mesogenic properties of the novel series are compared with other structurally similar homologous series.
- Chauhan,Doshi
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- A practical chlorination of tert-butyl esters with PCl3 generating acid chlorides
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For the first time, using PCl3, a range of tert-butyl esters is chlorinated successfully, allowing access of both aromatic acid chlorides and aliphatic acid chlorides in good yields. The method features simple reaction conditions and wide substrate scope. Various tert-butyl esters including aryl esters, alkenyl esters, and alkyl esters were tolerated well in the reaction. A plausible mechanism is proposed.
- Wu, Xiaofang,Zhou, Lei,Yang, Ruoqi,Guo, Fengzhe,Tang, Zi-Long,Xiao, Jing
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- Synthesis and characterization of novel rod-like ester-based liquid crystalline homologous series: Effect of tert-butyl tail on mesomorphism
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A new rod-like homologous series consisting twelve compounds with central ester linkage and terminal tert-butyl group, tert-butyl [4-(4’-n-alkoxybenzoyloxy)benzoates] has been synthesized and characterized through standard spectroscopic techniques like UV, FT-IR, 1HNMR, DSC, POM, and XRD. Methoxy and ethoxy derivatives are nonmesogenic. Nematic mesophase commences as enantiotropy from propyloxy derivative and persists up to the octadecyloxy derivatives. Smectic A mesophase commences as monotropy from propyloxy to the octadecyloxy derivatives. The mesomorphic properties of present series are compared with other structurally related series to evaluate the effect of terminal tert-butyl group on mesomorphism. Two derivatives are subjected to in?vitro antimicrobial activity.
- Thakur, Shavi,Patel, Hemant N.
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- Study of Mesomorphism Through a Novel Homologous Series and Its Relation to Molecular Structure
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A novel homologous series 4-(4'-n-alkoxy benzoyloxy)-3-chloro phenyl azo,3',4'-dichlorobenzenes was synthesized with a view to understand and establish the relation between mesomorphism and the molecular structure. The novel series consists of 12 members, which showed commencement of monotropic nematic mesophase formation from the butoxy homologue and continued up to the hexadecyloxy homologue without exhibition of a smectic mesophase. The textures of the nematic mesophase are threaded or Schlieren in type. Transition temperatures were determined by an optical polarizing microscope equipped with a heating stage. Isotropic-nematic transition curve of the phase diagram behaved in normal manner with exhibition of odd-even effect. Solid-isotropic transition curve behaved descending tendency by adopting zigzag path up to the pentyloxy homologue; which include methoxy to propoxy homologues as nonmesomorphic derivatives. Thermal stability for the nematic is just a few degrees (1°C to 2°C). Analytical and spectral data support the molecular structures. The mesomorphic properties of present novel series are compared with structurally similar other known homologous series.
- Doshi,Chauhan
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- Synthesis of liquid crystals with lateral substituents in central and terminal benzene cores and their mesomorphic characterization
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A new homologous series consisting of 12 homologues central azo, and ester linkage with chloro lateral group at central and methyl group at the terminal benzene ring is synthesized and their mesomorphic properties are studied. All the homologues are mesogenic in nature. All the compounds are exhibiting enantiotropic nematic phase; no homologues shows smectic phase even in monotropic form. To evaluate the effect of lateral chloro group at central benzene ring and methyl group at terminal benzene ring, the present series is compared with structurally related homologous series. The structure of the synthesized compounds is characterized by standard spectroscopic method, viz., IR, UV, NMR, and MASS.
- Bhatt, Himanshu S.,Patel, Purvang D.,Dave, Jayrang S.
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- Mesomorphism dependence on lateral substitution of functional groups and their position in series: 4(4'-n-alkoxy benzoyloxy)-3-chloro phenyl azo-2"-methoxy benzenes
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Eleven homologues of the title series were synthesized. The methyl-to-pentyl derivatives are nonmesomorphic. The nematic mesophase commences from the sixth member of the series without any smectic phase. An odd-even effect in the nematic-isotropic transition curve is not observed. The nematic mesophase appeared as a threaded or a Schlieren-type texture as observed through a hot-stage polarizing microscope. The nematic-isotropic transition temperatures are between 89°C and 127°C with the mesomorphic range varying from 9°C to 44°C at the hexyl and tetradecyl derivative of the series, respectively. The nematic-isotropic transition curve initially rises and then falls in a normal manner as the series is ascended, but it abnormally rises beyond the 10th homologue. The series is enantiotropic nematic with a middle-ordered melting type. Analytical data support the structures of the molecules. The thermal stability and some other mesomorphic characteristics are compared with structurally similar homologous series. The average nematic-isotropic thermal stability is 105.4°C.
- Patel,Prajapati,Doshi
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- Synthesis of novel azoester homologous series of liquid crystalline behavior and the study of mesomorphism dependence on lateral substitution of middle phenyl ring
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The titled azoester liquid crystalline homologous series consists of eleven homologues. The pentyl to tetradecyl derivatives of the series are nematogenic without exhibition of smectogenic character. Rest of the members of the series are nonliquid crystalline in nature. Textures of the nematic mesophase are schlieren or threaded type. Transition curves in the phase diagram showed normal phase behavior. Transition temperatures and liquid crystal behavior observed under an optical polarizing microscope equipped with a heating stage. An odd even effect is observed for nematic-isotropic transition curve. Analytical and spectral data confirms the structures of the molecules. Present homologous series is predominant nematogenic and partly nonmesogenic. Average thermal stability for nematic is 125.33°C and nematogenic mesophase length varies between 12°C to 48°C at tetradecyl (C14) and octyl (C8) derivatives, respectively.
- Patel,Doshi, Ankita A.,Prajapati,Doshi
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- Dependence of thermotropic mesomorphism on molecular flexibility of changing tail group
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A novel chalconyl ester homologous series of liquid crystals has been synthesized and studied with a view to understanding and establishing the effect of molecular structure on liquid crystalline properties. Novel series consisted of 13 members (C1–C18) of a series. C1–C4 member of a series is nonliquid crystals and, the rest of the homolog members (C5–C18) are enantiotropically nematogenic with absence of smectogenic property. None of the homolog is monotropically mesomorphic. Transition and melting temperatures were determined by an optical microscope equipped with a heating stage. Textures of nematic phase are threaded or schlieren. Spectral and analytical data of selected members of a series confirms the molecular structures of homologues. Cr-N and N-I transition curves of a phase diagram behaved in normal manner with exhibition of odd-even effect of very short range as observed for N-I transition curve. Thermal stability for nematic is 122.0°C and the nematogenic mesophase ranges from 7.0°C to 38.0°C. Liquid crystal properties of a present series are compared with the structurally similar known homologous series.
- Solanki, Ravindra,Sharma, Vinay,Patel, Roshan
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- Study of the relation between molecular structure and mesomorphic behavior with reference to a novel homologous series: α-3-[4′-n-Alkoxy benzoyloxy] phenyl-β-3″-nitro benzoyl ethylenes
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The synthesis and mesomorphic properties of a novel homologous series is reported. With the exception of the methyl and ethyl homologues, all 11 members of the series exhibit mesomorphism enantiotropically. The propyl to pentyl homologues, and the tetradecyl and hexadecyl homologues are enantiotropic nematic without the exhibition of smectic mesomorphism; while the hexyl to dodecyl homologues exhibit smectic mesomorphism in addition to the nematic phase. The texture of the nematic-mesophase by optical polarizing microscopy is of the threaded or Schlieren type, and that of smectogenic homologues is of the focalconic fan type. A phase diagram of the series shows a typical trend. Analytical and spectral data confirm the molecular structure of the compounds. Transition temperatures and mesomorphic properties are determined by optical polarizing microscopy. Smectic and nematic thermal stabilities are 125°C and 167°C, respectively. The series is predominantly nematogenic and partly smectogenic with middle-order melting type, and the smectic and nematic-mesophase ranges vary from 8°C to 22°C and 9°C to 56°C, respectively. The mesomorphic properties of the novel series are compared with other structurally similar homologous series.
- Chaudhari,Doshi
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- Synthesis and evaluation of liquid crystalline properties of a novel homologous series: α-3-[4′-n-alkoxy benzoyloxy] phenyl-β- 4″-nitro benzoyl ethylenes
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The titled homologous series consists of 11 members. The methyl and ethyl homologues are nonmesomorphic because of very high melting points, however, the propyl to hexadecyl derivatives are enantiotropic nematic with absence of smectogenic. The texture of nematic mesophase is threaded or Schlieren. The nematic-isotropic transition curve of the phase diagram behaves in a normal manner with the exhibition of an odd-even effect. The transition temperatures of the series and liquid crystal properties are observed through optical polarizing microscopy and a hot stage. The novel materials were characterized by elemental analysis, infrared, and 1H NMR spectroscopy. Analytical data support the molecular structures. The liquid crystal properties of the novel series are compared with structurally similar homologous series. The novel series is entirely nematogenic with absence of smectic character and of a middle-ordered melting type. The nematic-isotropic thermal stability varies between around 120°C and 180°C.
- Suthar,Doshi, Ankita A.,Doshi
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- N-Aroyloxylthioxo-naphthalimides as DNA photocleavers of aroyloxyl oxygen radicals: Synthesis, evaluation, and substituents' effect
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Novel N-Aroyloxylthioxo-naphthalimides as highly efficient 'time-resolved' DNA photocleavers of aroyloxyl radicals type were designed and synthesized. The substituents at the aroyloxyl moiety have an important and unusual influence on the DNA photocleavage, and DNA photodamages of the compounds were unusually not depended on the electronic effects of substituents on the corresponding oxygen-centered radicals. With AM1 semi-empirical quantum calculation, it was found that their photocleaving activities were correlated with the densities of electron clouds on the N-O bonds in the triplet state. N-(m-Dichloro-benzoyloxy) -thioxo-naphthalimide could photodamage DNA effectively at less than the concentration of 2μM.
- Xu, Yufang,Huang, Xiayu,Qian, Xuhong,Yao, Wei
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- Behavior of organic compounds confined in monoliths of sol-gel silica glass. Effects of guest-host hydrogen bonding on uptake, release, and isomerization of the guest compounds
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Various proteins, catalysts, and other compounds can be encapsulated or diffused into porous sol-gel glasses, but little is known about their interactions with the glass matrix. We report unexpectedly large effects that hydrogen bonding between organic co
- Badjic,Kostic
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- The Dependence of Mesomorphism on the Terminal Group
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A novel azoester homologous series of liquid crystals (LCs) was synthesized and studied with a view to understanding and establishing the effect of molecular structure on LC behavior. The series consists of twelve members. All the members of the series exhibit a nematogenic mesophase. The methoxy and propyloxy derivatives are monotropic and the rest of the homologs are enantiotropic nematogenic. Smectic mesophase formation is completely absent. Transition temperatures and the textures of the nematic phase were observed and determined through an optical polarizing microscope equipped with a heating stage. Transition curves (CrN and NI) of a phase diagram behave in a normal manner except for the hexadecyloxy homolog which deviates from normal behavior in the NI transition curve. The NI transition curve exhibits an odd-even effect. The textures of the nematic phase are threaded or Schlieren in type. The average thermal stability for the nematic phase is 158°C. The nematogenic mesophase length ranges from 27°C to 226°C. The analytical and spectral data confirms the molecular structures of the homologs. The LC properties of the presently investigated novel series are compared with a structurally similar known series. The novel azoester series is entirely nematogenic without exhibition of smectogenic character.
- Makwana,Prajapati,Chahar,Doshi
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- Dependence of mesomorphism on tail group in combination with a lateral methoxy group
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A novel homologous series of esters with a lateral methoxy group and terminal n-heptyl cinnamate group was synthesized and studied to investigate mesomorphic behavior in relation to structure. The twelve membered series consists of methoxy to pentyloxy derivatives that are nonmesomorphic and the rest of the homologs as smectegenically mesomorphic, including C6 and C7 monotropic smectic and C8 to C16 enantiotropic smectic without exhibition of any nematic property. The textures of smectogenic mesophases are focal conic fan shaped or batonates of the type smectic-A or Schlieren-C. An odd-even effect is exhibited by the Sm-I transition curve in the phase diagram. The Cr-Sm and Sm-I transition curves behave in a normal manner. Transition temperatures and textures were determined on an optical polarizing microscope, equipped with a heating stage. Some representative members were characterized by IR, H1NMR, mass spectra, and elemental analysis. Analytical data support the molecular structures of the homologs. Mesomorphic properties of the present novel series are compared with the structurally similar known series. The present series is smectogenic only, whose thermal average stability is 89.8°C and of a middle-ordered melting type.
- Travadi,Vadodaria,Ladva,Doshi
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- Dependence of mesomorphism on geometrical shapes of isomeric and nonisomeric series of chalconyl esters
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A meta substituted chalconyl ester homologous series: RO?C6H4?COO?C6H4(meta)?CO?CH?CH?C6H4?OC12H25(n)(para) is synthesized and studied with a view to understanding the effect of molecular substitution at meta position in a molecular structure on thermotropic liquid crystal properties. The novel homologous series consists of thirteen homologues (C1 to C18). All the homologues except the nonliquid crystal homologues C1, C2, C3 are enantiotropic nematic with the absence of smectic properties. The transition and melting temperatures were determined by an optical polarizing microscopy (POM) equipped with a heating stage. Textures of a nematic phase are threaded or Schlieren. Transition curves (Cr-N/I and N-I) behave in normal manner except homologues between C10 and C14 of N-I curve, which show negligible deviation from normal and a smooth descending tendency. The N-I transition curve exhibits an odd-even effect up to C10 homologue and then the odd-even effect disappears for higher homologues. Analytical and the spectral data support the molecular structures. Thermal stability for nematic is 107.3°C and the mesophase lengths range between 13.0°C and 35.0°C at the C18 and C12 homologues respectively. Group efficiency order for nematic is derived on the basis of thermal stability as ?OC12H25(n) (linear) > ?OC12H25(n) (nonlinear) > ?OC16H33 (nonlinear).
- Patel, Priya K.,Shah
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- Dependence of thermotropic mesomorphism on flexible tail group
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A novel homologous series RO-C6H4-COO-C6H4-CO-CH:CH-C6H4-OC12H25 of chalcones have been synthesized and studied with a view to understand and establish the effects of molecular structure on liquid crystal (LC) properties of a substance. Liquid crystal properties of a novel series commences from C6 homologue and continue upto the last C18 homologue derivative of a series, as enantiotropically nematogenic without exhibition of smectogenic characteristic. The rest of the homologues (C1 to C5) are nonliquid crystals (NLC). Transition temperatures of homologues (C1 to C18) are determined by an optical polarizing microscopy equipped with a heating stage. Textures of a nematic phase are threaded or schlieren. Transition curves of a phase diagram behaved in normal manner except for C18 member of a series, which drastically behaved with abnormal manner. N-I transition curve exhibits odd–even effect. Average thermal stability for nematic is 110.25°C and mesophase length ranges from 10°C to 39°C. Analytical and spectral data supported the molecular structures of homologues. LC properties of present novel series are compared with structurally similar other known homologous series. Thus, present novel series of chalcones is partly nematogenic and of middle-ordered melting type.
- Patel, Priya K.,Shah
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- Mesomorphism Dependence on Terminal/Lateral Substitution of Nonlinear Azoester Molecules
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A novel azo ester homologous series of liquid crystals (LCs) 2(4′-n-alkoxy benzoyloxy) napthyl 1 azo-3″ nitrobenzenes consists of eleven members of a series with enantiotropic nematogenic mesophase formation and without exhibition of smectogenic property by all the eleven homologs. The nematogenic mesophase textures are threaded or Schlieren. Solid-nematic and nematic-isotropic transition curves of the phase diagram behave in normal manner except for the decyloxy, dodecyloxy, and tetradecyloxy homologs. Analytical and spectral data confirm the molecular structures of homologues. Thermal stability for the nematic phase is 132.6°C, and the degree of mesomorphism varies between 34°C and 79°C and the series if of a middle-ordered melting type. An odd-even effect is observed for the N-I transition curve with alternation of transition temperatures. The LC behavior of the series is compared with other structurally similar known homologous series to establish the relation between mesomorphism and molecular structure.
- Prajapati,Doshi
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- SALICYLOYLASPARTATE AS AN ENDOGENOUS COMPONENT IN THE LEAVES OF PHASEOLUS VULGARIS
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An amide conjugate of o-methoxybenzoic acid and aspartic acid has been isolated from bean leaves.After extraction and methylation of plant material, this compound was isolated as two isomeric monoethyl monomethyl esters.The ethylation of the aspartyl carboxyl groups was shown to be a likely result of an extraction procedure utilising acidified ethanol, the methylation of the aromatic hydroxy of the methoxy group to be due to the derivatisation procedure.Studies with pentafluorobenzylation confirmed that the endogenous compound is o-hydroxybenzoylaspartate. Key Words: Phaseolus vulgaris; Leguminosae; leaves; aspartate amide; salicyloylaspartate.
- Bourne, David J.,Barrow, Kevin D.,Milborrow, B. V.
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- Synthesis and study of a novel azoester mesogenic homologous series: 4-[4′-n-alkoxy benzoyloxy]-naphthylazo-4″-acetyl benzenes
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The synthesis and mesomorphic properties of a novel azoester homologous series consisting of 12 members is reported. The methyl to butyl derivatives of the series are non-mesogenic, and the others are enantiotropically smectogenic and/or nematogenic. The nematic mesophase shows a threaded or Schlieren texture and smectic mesophase shows a focal conic fan-shaped texture of the SmA or the SmC. The smectic and nematic thermal stabilities are 137.4 and 166.6 respectively. Analytical data support the molecular structures. The transition temperatures of the homologues are determined using optical polarizing microscopy. An odd-even effect is observed for the nematic-isotropic transition curve and the series is equally smectogenic and nematogenic over a wide temperature range, and the melting points are in the middle order. The mesogenic properties of the present series are compared with a structurally similar homologous series. Copyright Taylor & Francis Group, LLC.
- Patel,Chauhan,Doshi
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- Synthesis of novel ester series and study of its mesomorphism dependence on terminal end group with lateral-OCH3 group
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Novel liquid crystal (LC) materials of ester derivatives were synthesized and studied with a view to understanding and establishing the effects of molecular structure on LC properties. The novel molecules consist of two phenyl rings bonded through-COO-central group and a laterally substituted methoxy group with-OCnH2n+1 as well as-COOCH3 terminal end groups, and yielded 12 homologous members of an ester series. The C1 to C3 members are nonmesomorphic, the C4 to C12 members are enantiotropic nematic only, and the C14 to C16 members are enantiotropically smectogenic in addition to nematogenic. Transition temperatures and the textures of LC state were observed through an optical polarizing microscope (POM) equipped with a heating stage. The textures of nematic phase are threaded or Schlieren, and that of smectic phase are focal conic of the type A or C. Transition curves of a phase diagram behave in normal manner with the exhibition of an odd-even effect (only N-I). Analytical and spectral data support the molecular structures of the novel ester derivatives. The LC properties of the present series are compared with structurally similar other known series. The average thermal stability of the series is 93°C for smectic and 120.88°C for nematic and the mesogenic phase length ranges between 2°C and 46°C.
- Vadodaria,Ladva,Doshi,Travadi
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- Study of Y-shaped liquid crystalline materials with polar nitro substituent
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A new homologous series of Y-shaped liquid crystals namely 4-Nitro-[2′4′bis (4″-n-alkoxybenzoyloxy)] phenyl bisazobenzenes have been synthesized and its thermotropic properties studied on the hot stage of a polarizing microscope. The compounds consist four phenyl rings joined through ester and bisazo linkages with alkoxy and nitro as terminal substituents. The structures of synthesized compounds were confirmed by spectroscopic techniques such as FTIR, 1HNMR as well as elemental analysis. The compounds were found to exhibit enantiotropic nematic and smectic mesophases. The role of molecular shape, size and polarity of functional groups in the mesophases formation is discussed.
- Dixit, Sandhya
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- Mesomorphism Dependence of Chalconyl Derivatives on Position of -CH=CH- Unit
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A novel homologous series of heterocyclic chalconyl esters (C1 to C16) has been synthesized and studied with a view to understanding and establishing the effects of molecular structure on liquid crystal (LC) properties and the degree of liquid crystallinity. The C1 to C6 homologues are not liquid crystals, the C7 homologue is enantiotropic nematic, the C8 to C16 homologues are smectogenic in addition to nematogenic (C8 & C10 monotropic smectic). The texture of nematic phases are threaded or Schlieren and that of the smectic phase are fan-shaped smectic-A or smectic-C type. Transition temperatures and the textures of mesophases were determined by an optical polarizing microscope equipped with a heating stage. Transition curves Cr-I/M, Sm-N/N-Sm, and N-I showing phase behaviors of series in a phase diagram behave in normal manner. Thermal stability for smectic and nematic are 115.66°C and 126.83°C and their mesophase lengths minimum to maximum are 6.3 to 12.9°C and 6.9°C to 17.4°C, respectively. Analytical and spectral data confirms the molecular structures of homologues. LC properties of present novel series are compared with structurally similar other reported series.
- Rakhasia,Bhola,Bhoya
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- Mesomorphism Dependence on Terminal and Lateral Polar Groups in the Nonlinear Novel Azoester Series
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The synthesis of a novel azoester homologous series was carried out with a view to understanding and establishing the effect of molecular structure on liquid crystal (LC) behavior of a substance. The novel series consists of eleven homologs, and all are enantiotropically nematogenic without exhibition of any smectic property. Transition and melting temperatures, textures of LC were determined by an optical polarizing microscope equipped with a heating stage. The textures of the nematic phase are threaded or Schlieren. Transition curves of a phase diagram behave in normal manner. The nematic-isotropic transition curve exhibits an odd-even effect. Analytical and spectral data support and confirm the structures of the homologues. Average thermal stability for the nematic is 137.2°C. The mesomorphic phase length ranges from 15°C to 50°C. LC behavior of the novel series is compared with a structurally similar known homologous series. The novel azoester homologous series is entirely nematogenic without exhibition of smectogenic character and of a middle-ordered melting type.
- Prajapati,Doshi
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- Study of Novel Symmetrical Liquid Crystalline Ester Dimers
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A novel homologous series of 12 symmetrical dimers, viz. 1,1'-Bis[4-(4'-n-alkoxy benzoyloxy)-3-methyl phenyl] cyclohexanes is reported. Nematogenic mesophase commences from the heptyloxy homologue dimer and continues up to the hexadecyloxy dimer in an enantiotropic manner without the exhibition of any smectogenic behavior. The rest of the dimers from methoxy to hexyloxy are nonmesogenic. The textures of the nematic phase are threaded or Schlieren. The transition temperatures and textures of the nematic phase were determined by an optical polarizing microscope equipped with a heating stage. Curves (solid-isotropic/nematic and N-I) of a phase diagram showing mesomorphism behave in normal manner except for a minor deviation at the dodecyloxy derivative. The analytical and spectral data confirm the molecular structure of dimers. The nematogenic mesophase lengths vary between 3.3°C and 26.6°C. The average thermal stability for nematic is 108.26°C; series is partly nematogenic with middle ordered melting type and low degree of mesomorphism. Liquid crystal properties of novel dimer series are compared with the structurally similar other known series.
- Kotadiya,Bhoya
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- Folding Patterns in a Family of Oligoamide Foldamers
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A series of small, unsymmetrical pyridine-2,6-dicarboxylamide oligoamide foldamers with varying lengths and substituents at the end groups were synthetized to study their conformational properties and folding patterns. The @-type folding pattern resembled the oxyanion-hole motifs of enzymes, but several alternative folding patterns could also be characterized. Computational studies revealed several alternative conformers of nearly equal stability. These folding patterns differed from each other in their intramolecular hydrogen-bonding patterns and aryl-aryl interactions. In the solid state, the foldamers adopted either the globular @-type fold or the more extended S-type conformers, which were very similar to those foldamers obtained computationally. In some cases, the same foldamer molecule could even crystallize into two different folding patterns, thus confirming that the different folding patterns are very close in energy in spite of their completely different shapes. Finally, the best match for the observed NOE interactions in the liquid state was a conformation that matched the computationally characterized helix-type fold. Erase and refold: Like peptides, oligoamide foldamers fold into a number of different conformers that are very close in energy (see picture, stability energies in kcal mol-1 given in parentheses). By using a combination of computational, single-crystal X-ray diffraction, and NMR spectroscopic studies, these folding patterns have been identified and characterized for a family of seven different foldamers with varying substituents.
- Kortelainen, Minna,Suhonen, Aku,Hamza, Andrea,Pápai, Imre,Nauha, Elisa,Yliniemel?-Sipari, Sanna,Nissinen, Maija,Pihko, Petri M.
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- Synthesis and Characterization of a Novel Azoester Homologous Series
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An azoester homologous series of 4-(4'-n-alkoxybenzoyloxy) 3-methylphenyl azo-2''-chloro-3''-methyl benzenes consisting of 12 homologues was synthesized. The methoxy to pentyloxy homologues are nonmesogenic, the hexyloxy to dodecyloxy homologues are monotropic nematic and the tetradecyloxy to hexadecyloxy homologues are enantiotropic nematic. The textures of the nemetic phase are of the threaded or schlieren type. Transition curves showing phase behavior in a phase diagram behave in normal manner, with the exception of the last enantiotropic homologue. An odd-even effect is observed for the nematic-isotropic transition curve. Thermal phase transitions were observed through an optical polarizing microscope equipped with a heating stage. Analytical and spectral data support the molecular structures of the homologue molecules. Smectogenic character is totally absent from all the novel homologues. The average thermal stability for the nematic phase is 121.5 °C. Mesogenic properties of the present novel series are compared with other structurally similar known series.
- Kotadiya,Khunt,Bhoya
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- Study of Liquid Crystal Behavior and Dependence on Additional Central Bridge of Ester Homologous Series
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A novel homologous series of esters was synthesized and studied with a view to understanding and establishing the effects of molecular structure on liquid crystal (LC) properties. The series consists of 11 members, and all exhibit enantiotropically the smectogenic mesophase. The nematogenic mesophase is totally absent. The textures of smectic phases are of the type A or C. The Sm-I transition curve of the phase diagram behaves in abnormal manner. The average Sm-I thermal stability is 124.53°C with mesomorphic phase length between 6.5°C and 52.3°C and is of a middle-ordered melting type. LC properties of the novel series are compared with a structurally similar other known series. Analytical and spectral data of the homologous match the molecular structure.
- Marathe, Rajesh B.,Doshi
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- The mesogenic behavior of isomeric and nonisomeric series of novel azoesters. 4-(4′-n-Alkoxy Benzoyloxy) Phenylazo-2″-bromobenzenes
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A novel homologous series: 4-(4′-n-alkoxy benzoyloxy) phenylazo-2″-bromobenzenes is synthesized and studied with a view to understanding and establishing the effects of molecular structure on mesogenic behavior in a series. The mesogenic property commences from fifth homologue to the last homologue. The transition temperatures of the series are relatively low ranging between 68.C and 143.C. The mesogenic range varies between 6°C and 22°C. The novel azoester series is nematogenic without exhibition of any smectogenic property and an average thermal stability of 89.4°C. The mesogenic behavior of the novel series is compared with structurally similar isomeric/nonisomeric other known series.
- Kotadiya,Khunt,Bhoya
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- Dependence of liquid crystallinity on molecular rigidity
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A novel homologous series of liquid crystals (LC) of chalconyl derivatives is synthesized and studied with a view to understanding and establishing the effects of molecular structure on liquid crystal properties. The novel series consists of 12 homologues. Nematogenic LC property commences from C3 and continues up to C14 and the smectogenic mesophase is exhibited from C4 to C16. The C3 homologue is a monotropic nematic and the rest of the homologues are enantiotropically smectic and nematic or only smectic (C16). Transition curves Cr-Sm, Sm-N, Cr-I, and N-I behave in normal manner with exhibition of odd-even effect, showing phase behaviors of the series.
- Rakhasia,Bhoya
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- PCl3-mediated transesterification and aminolysis of tert-butyl esters via acid chloride formation
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A PCl3-mediated conversion of tert-butyl esters into esters and amides in one-pot under air is developed. This novel protocol is highlighted by the synthesis of skeletons of bioactive molecules and gram-scale reactions. Mechanistic studies revealed that this transformation involves the formation of an acid chloride in situ, which is followed by reactions with alcohols or amines to afford the desired products.
- Wu, Xiaofang,Zhou, Lei,Li, Fangshao,Xiao, Jing
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- Metathesis-active ligands enable a catalytic functional group metathesis between aroyl chlorides and aryl iodides
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Current methods for functional group interconversion have, for the most part, relied on relatively strong driving forces which often require highly reactive reagents to generate irreversibly a desired product in high yield and selectivity. These approaches generally prevent the use of the same catalytic strategy to perform the reverse reaction. Here we describe a catalytic functional group metathesis approach to interconvert, under CO-free conditions, two synthetically important classes of electrophiles that are often employed in the preparation of pharmaceuticals and agrochemicals—aroyl chlorides (ArCOCl) and aryl iodides (ArI). Our reaction design relies on the implementation of a key reversible ligand C–P bond cleavage event, which enables a non-innocent, metathesis-active phosphine ligand to mediate a rapid aryl group transfer between the two different electrophiles. Beyond enabling a practical and safer approach to the interconversion of ArCOCl and ArI, this type of ligand non-innocence provides a blueprint for the development of a broad range of functional group metathesis reactions employing synthetically relevant aryl electrophiles.
- Lee, Yong Ho,Morandi, Bill
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- A novel homologous series of thermotropic mesogens of ethylene derivatives: α-4-[4′-n-Alkoxy Benzoyloxy] phenyl β-4″ methoxy benzoyl ethylenes
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A novel homologous series consists of 12 compounds. The shorter chain homologues do not show liquid crystal phases, but from six carbons onwards, the nematic phase is exhibited enantiotropically, with some members also showing a smectic phase. The phase behavior of the transition curves of the series shows a usual trend. The texture of the nematic phase is the threaded or Schlieren type and that of smectic phase is a smectic A. An odd-even effect is observed for smectic-nematic and nematic-isotropic transition curves. Analytical data confirm the molecular structure. The transition temperatures were determined by an optical polarizing microscopy. The mesogenic properties of the novel series are compared with a structurally similar homologous series. The average smectic-nematic and nematic-isotropic thermal stabilities are 133.4°C and 159.8°C, respectively, with a mesogenic temperature range of 10°C to 62°C.
- Chauhan,Doshi
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- A comparative study of mesomorphism in symmetric and nonsymmetric dimers
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A homologous series consisting of 12 homologue symmetrical dimers, viz., bis(4-n-alkoxy benzoyloxy) 2,2-diphenyl propanes was synthesized, studied, and evaluated to establish the relation between molecular structure and mesomorphic properties on comparative basis with nonsymmectric dimers. The methoxy to pentyloxy homologue dimers, the novel symmetric series, are nonmesogenic. Mesomorphism commences from the hexyloxy homologue as smectic and nematic. The hexyloxy to decyloxy dimers possess smectogenic character with nematogenic character and the dodecyloxy to hexadecyloxy homologue dimers exhibit nematogenic character without the exhibition of smectogenic character. All the mesogenic homologues are enantiotropic mesomorphs. The smectic and nematic thermal stability of series is 129.0°C and 147.7°C, respectively, and mesomorphic phase length varies between 18°C for the hexadecyloxy homologue and 56°C for the heptyloxy homologue.
- Kotadiya,Khunt,Bhoya
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- One-step Conversion of Amides and Esters to Acid Chlorides with PCl3
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A general and efficient iodine-promoted chlorination of amides and esters with phosphorus trichloride is described. For the first time. Various inactivated amides including secondary and tertiary amides were directly converted to the corresponding acid chlorides in one-step. The substrate scope of methyl esters including aromatic and aliphatic esters was also explored under this system. This method is simple, scalable and wide in scope, which provides an approach to preparation of these acid chlorides.
- Li, Fangshao,Wu, Xiaofang,Guo, Fengzhe,Tang, Zi-Long,Xiao, Jing
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- Mesomorphism dependence on the combined effect of molecular rigidity and flexibility
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A novel liquid crystalline (LC) homologous series of azoesters with a laterally substituted methoxy group RO-C6H4-COO-C6H3-(-OCH3)-N═N-C6H4-COO-C4H9(n) has been synthesized and studied with a view to understanding the effect of molecular structure on thermotropic mesomorphism. The novel homologous series consists of thirteen homologues (C1–C18). The C1–C5 homologues are nonliquid crystals. The C6 and C7 homologues are only enantiotropically nematogenic and the rest of the mesomorphic homologues (C8–C18) are enantiotropically smectogenic and nematogenic. Transition temperatures and the textures of the mesophases were determined using an optical polarizing microscope (POM) equipped with a heating stage. The novel azoester homologues were characterised and confirmed using their analytical, spectral and thermometric data. Transition curves Cr-M/I, Sm-N and N-I behaved in normal manner without (Sm-N) and with (N-I) exhibition of odd-even effect respectively in a phase diagram. Thermal stabilities for smectic and nematic are 100.0°C and 127.7°C whose, mesomorphic phase length vary from 13.0°C to 24.0°C and 11.0°C to 33.0°C, respectively. The mesomorpism is compared with other known series.
- Jadeja,Patel
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- Exploring unsymmetrical dyads as efficient inhibitors against the insect β-N-acetyl-d-hexosaminidase OfHex2
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The GH20 β-N-acetyl-d-hexosaminidase OfHex2 from the insect Ostrinia furnacalis (Guene?e) is a target potential for eco-friendly pesticide development. Although carbohydrate-based inhibitors against β-N-acetyl-d- hexosaminidases are widely studied, highly
- Chen, Qi,Guo, Peng,Xu, Lin,Liu, Tian,Qian, Xuhong,Yang, Qing
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- Dependence of Mesomorphism on Molecular Rigidity with Reference to Lateral Substitution and Central Bridge
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A novel mesogenic ester homologous series is synthesized and studied with a view to understanding and establishing the effect of laterally substituted-OCH3 on mesomorphic behavior. The series consists of twelve members. C1 to C4 members are nonmesogenic, C6 to C12 are smectogenic in addition to nematogenic, and C14 to C16 are only smectogenic. The textures of smectic and nematic phases are A or C type and threaded or Schlieren, respectively. The transition curves in a phase diagram exhibit an odd-even effect and behave in normal manner except for the C14 and C16 derivatives in Sm-I transitions. Thermometric data were determined by an optical polarizing microscope equippedwith a heating stage. Average thermal stability for smectic and nematic are 107.7°C and 121.0°C, respectively. Smectogenic and nematogenicmesophase length ranges from 11.0 to 44.0°C and 12.0°C to 39.0°C, respectively. The mesomorphic properties of present series are comparedwith structurally similar other known series. Thus, present series is predominantly smectogenic and partly nematogenic ofmiddle ordered melting type.
- Travadi,Vadodaria,Ladva,Doshi
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- Mesomorphism Dependence on Molecular Structure
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A novel homologous series of liquid crystal (LC) derivatives of general structure: RO·C6H4·COO·C6H3·OCH3(ortho)CH = CH·COO·(n)C5H11 was synthesized and studied with a view to understanding the effect of molecular structure on liquid crystal behavior with reference to lateral-OCH3 and terminal end group. Homologous series consists of 12 derivatives (C1-C16), the first five (C1-C5), and the last (C16) members are not liquid crystals and the rest of the homologs (C6-C14) are enantiotropically smectogenic without exhibition of the nematic phase. The textures of the smectic phases are focal conic fan shaped or batonets of smectic-A or smectic-C. Average thermal stability for smectic is 81.8°C and mesophase length ranges from 9°C to 31°C. Transition curves of a phase diagram (Sm-I and Cr-Sm/I) behave in a normal manner. The Sm-I transition curve exhibits an odd-even effect. Analytical and spectral data support the molecular structures. The series is smectogenic of a middle ordered melting type. LC properties of the present series are compared with structurally similar known homologous series. Transition temperatures were determined by an optical polarizing microscope equipped with a heating stage.
- Travadi,Vadodaria,Ladva,Doshi
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- Study of the Effect of Lateral Substitution on Mesogenic Behavior with Reference to -CH=CH- Unit
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A novel cinnamate ester homologous series has been synthesized and studied with a view to understanding and establishing the effects of molecular structure on liquid crystal (LC) properties with a focus on the highly polar methoxy group as a lateral substituent. The series consists of twelve homologs; of which C1-C5 are nonmesogenic, and the rest of the homologs are enantiotropically smectogenic or and nematogenic. The texture of nematic phases is threaded or Schlieren and that of the smectic is either smectic A or C, as recognized and determined through an optical polarizing microscope equipped with a heating stage. The Sm-N I and N-I transition curves exhibit odd-even effects and behave in normalmanner. The Cr-IMbehaves in normalmanner. Analytical and spectral data confirm the molecular structures of homologs. The average thermal stabilities for smectic and nematic are 125.3 C and 129.8 C, respectively, whose total mesophase length varies from 13 C to 51 C. Some LC properties of present series are compared with the structurally similar known series.
- Travadi,Vadodaria,Ladva,Doshi
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- Synthesis, characterization, and antimicrobial analysis of 5-phenyl-4-((2-(piperazin-1-yl)ethyl)thio)-1,2,3-oxadiazole analogs through in vitro and in silico approach
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1,3,4-Oxadiazoles and 1,2,3-oxadiazoles are well known heterocyclic compounds, which acts both as biomimetic and reactive pharmacophores. Many of them are key compounds with potential biological activities. A sequence of novel 1,2,3-oxadiazole derivatives
- Khanum, Shaukath Ara,Martiz, Reshma Mary,Ramu, Ramith,Ranganatha, V. Lakshmi,V, Rashmi
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- 3-(3'-hydroxybutyl) isobenzofuran-1(3H)-ketone derivative as well as composition, preparation method and application thereof
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The invention belongs to the field of medicines, and particularly relates to a 3-(3-hydroxybutyl) isobenzofuran-1(3H)-ketone derivative as well as a composition, a preparation method and application thereof, and the derivative is a compound with a structu
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Paragraph 0071; 0085; 0088; 0091; 0096; 0098-0099
(2021/05/15)
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- Xylochemical synthesis and biological evaluation of shancigusin c and bletistrin g
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The biological activities of shancigusin C (1) and bletistrin G (2), natural products isolated from orchids, are reported along with their first total syntheses. The total synthesis of shancigusin C (1) was conducted by employing the Perkin reaction to forge the central stilbene core, whereas the synthesis of bletistrin G (2) was achieved by the Wittig olefination followed by several regiose-lective aromatic substitution reactions. Both syntheses were completed by applying only renewable starting materials according to the principles of xylochemistry. The cytotoxic properties of shancigusin C (1) and bletistrin G (2) against tumor cells suggest suitability as a starting point for further structural variation.
- Efferth, Thomas,Geske, Leander,Kauhl, Ulrich,Opatz, Till,Saeed, Mohamed E. M.,Schüffler, Anja,Thines, Eckhard
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- Synthesis and antioxidant activities of berberine 9-: O -benzoic acid derivatives
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Although berberine (BBR) shows antioxidant activity, its activity is limited. We synthesized 9-O-benzoic acid berberine derivatives, and their antioxidant activities were screened via ABTS, DPPH, HOSC and FRAP assays. The para-position was modified with halogen elements on the benzoic acid ring, which led to an enhanced antioxidant activity and the substituent on the ortho-position was found to be better than the meta-position. Compounds 8p, 8c, 8d, 8i, 8j, 8l, and especially 8p showed significantly higher antioxidant activities, which could be attributed to the electronic donating groups. All the berberine derivatives possessed proper lipophilicities. In conclusion, compound 8p is a promising antioxidant candidate with remarkable elevated antioxidant activity and moderate lipophilicity.
- Liu, Yanfei,Long, Shuo,Zhang, Shanshan,Tan, Yifu,Wang, Ting,Wu, Yuwei,Jiang, Ting,Liu, Xiaoqin,Peng, Dongming,Liu, Zhenbao
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p. 17611 - 17621
(2021/05/29)
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- λ-shaped to T-shaped azo diester mesogens having methyl (–CH3)/methoxy(–OCH3) terminal substituents with trisubstituted benzene
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A two new homologous series of λ-shape to T-shape mesogenic azo diesters were synthesized, and their thermotropic properties were studied by differential scanning calorimetry and a hot-stage polarizing optical microscope. The difference between these two series is in the structure of terminal substituents methyl (–CH3) for series I and methoxy (–OCH3) for series II at one terminus. Structure variation from λ-shape to T-shape as we go from lower members to higher members is discussed. In the series I, methoxy to n-pentyloxy derivatives are non-mesogenic. n-hexyloxy derivative exhibits only monotropic nematic mesophase. n-heptyloxy to n-dodecyloxy derivatives exhibit monotropic smectic C mesophase. n-tetradecyloxy derivative exhibits enantiotropic SmA mesophase, whereas n-hexadecyloxy derivatives exhibit monotropic Smectic A mesophase. In series II, methoxy to n-hexyloxy derivatives are non-mesogenic. n-heptyloxy and n-octyloxy derivatives exhibit monotropic smectic C mesophase. Smectic A mesophase commences from the n-decyloxy derivative as a monotropic and persists up to the last member synthesized. The mesomorphic properties of the present series were compared with each other and with the structurally related mesogenic homologous series to evaluate the effect of methyl (–CH3)/methoxy (–OCH3) substituents as well as variation in the shape of the molecule by varying the alkoxy chain length of the bulky lateral substituent on mesomorphism.
- Duan, Yongtao,Koshti, Rohit R.,Kumar Ameta, Rakesh,Patel, H. N.,Sangani, Chetan B.,Tarpada, Umesh P.,Vyas, Akshay,Yao, Yongfang
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- Remarkably Efficient Iridium Catalysts for Directed C(sp2)-H and C(sp3)-H Borylation of Diverse Classes of Substrates
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Here we describe the discovery of a new class of C-H borylation catalysts and their use for regioselective C-H borylation of aromatic, heteroaromatic, and aliphatic systems. The new catalysts have Ir-C(thienyl) or Ir-C(furyl) anionic ligands instead of the diamine-type neutral chelating ligands used in the standard C-H borylation conditions. It is reported that the employment of these newly discovered catalysts show excellent reactivity and ortho-selectivity for diverse classes of aromatic substrates with high isolated yields. Moreover, the catalysts proved to be efficient for a wide number of aliphatic substrates for selective C(sp3)-H bond borylations. Heterocyclic molecules are selectively borylated using the inherently elevated reactivity of the C-H bonds. A number of late-stage C-H functionalization have been described using the same catalysts. Furthermore, we show that one of the catalysts could be used even in open air for the C(sp2)-H and C(sp3)-H borylations enabling the method more general. Preliminary mechanistic studies suggest that the active catalytic intermediate is the Ir(bis)boryl complex, and the attached ligand acts as bidentate ligand. Collectively, this study underlines the discovery of new class of C-H borylation catalysts that should find wide application in the context of C-H functionalization chemistry.
- Chattopadhyay, Buddhadeb,Hassan, Mirja Md Mahamudul,Hoque, Md Emdadul
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supporting information
p. 5022 - 5037
(2021/05/04)
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- Preparation method of benzoyl chloride compound
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The invention provides a preparation method of a benzoyl chloride compound. The preparation method comprises the following step: with a trichloromethyl benzene compound and a benzoic acid compound as raw materials and ferric oxide as a catalyst, carrying out a catalytic reaction to prepare the benzoyl chloride compound. According to the method disclosed by the invention, the benzoyl chloride compound can be obtained under the condition of not using a solvent, yield is up to 95% or above, atom economy is good, cost is lower, operation is simpler, more convenient and safer, the treatment amount of three wastes is smaller, the three wastes is easier to treat, and the method is more suitable for industrial production.
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Paragraph 0079-0083
(2021/06/22)
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- Photochemical Activation of Aromatic Aldehydes: Synthesis of Amides, Hydroxamic Acids and Esters
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A cheap, facile and metal-free photochemical protocol for the activation of aromatic aldehydes has been developed. Utilizing thioxanthen-9-one as the photocatalyst and cheap household lamps as the light source, a variety of aromatic aldehydes have been activated and subsequently converted in a one-pot reaction into amides, hydroxamic acids and esters in good to high yields. The applicability of this method was highlighted in the synthesis of Moclobemide, a drug against depression and social anxiety. Extended and detailed mechanistic studies have been conducted, in order to determine a plausible mechanism for the reaction.
- Nikitas, Nikolaos F.,Apostolopoulou, Mary K.,Skolia, Elpida,Tsoukaki, Anna,Kokotos, Christoforos G.
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supporting information
p. 7915 - 7922
(2021/05/03)
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- Tumor diagnosis and treatment fluorescent probe for targeting tumor Wolburg effect
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The invention discloses a tumor diagnosis and treatment fluorescent probe for targeting tumor Warburg effect, and the structure of the fluorescent probe is shown as a formula (I). The fluorescent probe can be directly used in a cell line to analyze and detect the expression degree of tumor cell GLUT1 protein, so as to complete the screening of tumor cells. Meanwhile, tumor cell proliferation is inhibited by directly blocking the GLUT1 channel to inhibit intake of sugar nutritional ingredients by tumors. And an effective means and a useful tool are provided for early screening and diagnosis oftumors, development of new anti-tumor drugs and the like.
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- 1-(2-(4-methoxyphenyl)thiazolyl-4-yl)ethylamine and synthesis method thereof
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The invention belongs to the technical field of organic synthesis, and discloses 1-(2-(4-methoxyphenyl)thiazolyl-4-yl)ethylamine and a chemical synthesis method thereof. The method comprises the following steps: by taking 4-methoxybenzoic acid as a raw material, carrying out acylation, substitution, sulfonylation, substitution, hydrolysis, substitution, substitution and reduction reaction to prepare 1-(2-(4-methoxyphenyl)thiazolyl-4-yl)ethylamine. An efficient synthesis method is provided for synthesis of the compound.
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Paragraph 0008; 0030-0032; 0049-0051; 0068-0070
(2020/11/12)
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- Design, synthesis and biological evaluation of anthranilamide derivatives as potent SMO inhibitors
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A series of anthranilamide derivatives were designed and synthesized as novel smoothened (SMO) inhibitors based on the SMO inhibitor taladegib (LY2940680), which can also inhibit the SMO-D473H mutant, via a ring-opening strategy. The phthalazine core in LY2940680 was replaced with anthranilamide, which retained the inhibitory activity towards the hedgehog (Hh) signaling pathway as evidenced by a dual luciferase reporter gene assay. Compound 12a displayed the best inhibitory activity against the Hh signaling pathway with IC50 value of 34.09 nM, and exhibited better proliferation inhibitory activity towards the Daoy cell line (IC50 = 0.48 μM) than LY2940680 (IC50 = 0.79 μM).
- Ji, Dezhong,Xu, Yungen,Zhang, Jing-Jing,Zhang, Wanwan
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- Palladium-Catalyzed Chlorocarbonylation of Aryl (Pseudo)Halides Through In Situ Generation of Carbon Monoxide
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An efficient palladium-catalyzed chlorocarbonylation of aryl (pseudo)halides that gives access to a wide range of carboxylic acid derivatives has been developed. The use of butyryl chloride as a combined CO and Cl source eludes the need for toxic, gaseous carbon monoxide, thus facilitating the synthesis of high-value products from readily available aryl (pseudo)halides. The combination of palladium(0), Xantphos, and an amine base is essential to promote this broadly applicable catalytic reaction. Overall, this reaction provides access to a great variety of carbonyl-containing products through in situ transformation of the generated aroyl chloride. Combined experimental and computational studies support a reaction mechanism involving in situ generation of CO.
- Bismuto, Alessandro,Boehm, Philip,Morandi, Bill,Roediger, Sven
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supporting information
p. 17887 - 17896
(2020/08/19)
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- Preparation method of aromatic acyl chloride
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The invention discloses a preparation method of aromatic acyl chloride. An aromatic acyl chloride compound is prepared through a reaction of aryl carboxylic acid and phosphorus trichloride. The preparation method of the aromatic acyl chloride has the advantages that the phosphorus trichloride is taken as a chloride reagent, the corresponding acyl chloride is synthesized from the aryl carboxylic acid, so that the production cost is low, the operation is simple, a by-product is low in toxicity, the environmental friendliness is achieved, the yield is high, and the method is conductive to industrial production.
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Paragraph 0055-0058
(2019/07/11)
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- Preparation method of medicine-safinamide mesylate for treating Parkinson's disease
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The invention discloses a preparation method of medicine-safinamide mesylate for treating Parkinson's disease. The chemical name of the safinamide mesylate is (S)-2-[4-(3-fluorobenzyloxy)benzylamino]propionamide methanesulfonate (1), and the chemical form
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- Preparation method of amiodarone hydrochloride intermittent
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The invention belongs to the field of medicine synthesis, and relates to a preparation method of an amiodarone hydrochloride intermittent. The method is characterized by including the following stepsthat 1, under an alkaline condition, in the presence of a phase transfer catalyst, a compound 1 and a compound 2 are subjected to nucleophilic substitution reaction to obtain a compound 3; 2, under analkaline condition, the compound 3 is hydrolyzed to generate a compound 4; 3, the compound 4 is subjected to intramolecular aldol condensation, decarboxylation and dehydration to obtain a compound 5;4, a compound 6 and thionyl chloride are subjected to heating reaction to obtain a compound 7; 5, under the presence of lewis acid, the compound 5 and the compound 7 are subjected to friede-crafts acylation reaction to obtain a compound 8; 6, under the presence of lewis acid, the compound 8 is subjected to demethylation to generate a compound 9, namely the amiodarone hydrochloride intermittent 2-butyl-3-(4-hydroxybenzoyl)benzofuran. The preparation method of the amiodarone hydrochloride intermittent has the advantages of being short in reaction time, high in product purity and high in yield,and the amiodarone hydrochloride intermittent is suitable for large-scale industrial production.
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Paragraph 0019; 0055; 0059; 0064; 0068; 0072; 0076
(2019/01/13)
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- Preparation method of 4-methoxybenzoyl chloride
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The present invention discloses a preparation method of 4-methoxybenzoyl chloride and belongs to the technical field of medical technology. A technical problem to be solved relates to the more advanced preparation method of the 4-methoxybenzoyl chloride.
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Paragraph 0008; 0009; 0010
(2019/01/08)
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- An Efficient Synthesis of New 2-Aryl-5-phenylazenyl-1,3,4-oxadiazole Derivatives from N, N' -Diarylcarbonohydrazides
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A series of new 1,3,4-oxadiazoles conjugated to aromatic substituents by an azo linker was synthesized in a four-step reaction sequence, involving cyclodehydration of a N, N' -diacylhydrazine fragment and dehydrogenation of the neighboring hydrazine fragm
- Kedzia, Anna,Jasiak, Karolina,Kudelko, Agnieszka
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supporting information
p. 1745 - 1748
(2018/06/26)
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- Sea Urchin Embryo Model As a Reliable in Vivo Phenotypic Screen to Characterize Selective Antimitotic Molecules. Comparative evaluation of Combretapyrazoles, -isoxazoles, -1,2,3-triazoles, and -pyrroles as Tubulin-Binding Agents
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A series of both novel and reported combretastatin analogues, including diarylpyrazoles, -isoxazoles, -1,2,3-triazoles, and -pyrroles, were synthesized via improved protocols to evaluate their antimitotic antitubulin activity using in vivo sea urchin embryo assay and a panel of human cancer cells. A systematic comparative structure-activity relationship studies of these compounds were conducted. Pyrazoles 1i and 1p, isoxazole 3a, and triazole 7b were found to be the most potent antimitotics across all tested compounds causing cleavage alteration of the sea urchin embryo at 1, 0.25, 1, and 0.5 nM, respectively. These agents exhibited comparable cytotoxicity against human cancer cells. Structure-activity relationship studies revealed that compounds substituted with 3,4,5-trimethoxyphenyl ring A and 4-methoxyphenyl ring B displayed the highest activity. 3-Hydroxy group in the ring B was essential for the antiproliferative activity in the diarylisoxazole series, whereas it was not required for potency of diarylpyrazoles. Isoxazoles 3 with 3,4,5-trimethoxy-substituted ring A and 3-hydroxy-4-methoxy-substituted ring B were more active than the respective pyrazoles 1. Of the azoles substituted with the same set of other aryl pharmacophores, diarylpyrazoles 1, 4,5-diarylisoxazoles 3, and 4,5-diaryl-1,2,3-triazoles 7 displayed similar strongest antimitotic antitubulin effect followed by 3,4-diarylisoxazoles 5, 1,5-diaryl-1,2,3-triazoles 8, and pyrroles 10 that showed the lowest activity. Introduction of the amino group into the heterocyclic core decreased the antimitotic antitubulin effect of pyrazoles, triazoles, and to a lesser degree of 4,5-diarylisoxazoles, whereas potency of the respective 3,4-diarylisoxazoles was increased.
- Semenova, Marina N.,Demchuk, Dmitry V.,Tsyganov, Dmitry V.,Chernysheva, Natalia B.,Samet, Alexander V.,Silyanova, Eugenia A.,Kislyi, Victor P.,Maksimenko, Anna S.,Varakutin, Alexander E.,Konyushkin, Leonid D.,Raihstat, Mikhail M.,Kiselyov, Alex S.,Semenov, Victor V.
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p. 700 - 721
(2019/01/03)
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- Functional Group Transposition: A Palladium-Catalyzed Metathesis of Ar-X σ-Bonds and Acid Chloride Synthesis
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We describe the development of a new method to use palladium catalysis to form functionalized aromatics: via the metathesis of covalent σ-bonds between Ar-X fragments. This transformation demonstrates the dynamic nature of palladium-based oxidative addition/reductive elimination and offers a straightforward approach to incorporate reactive functional groups into aryl halides through exchange reactions. The reaction has been exploited to assemble acid chlorides without the use of high energy halogenating or toxic reagents and, instead, via the metathesis of aryl iodides with other acid chlorides.
- De La Higuera Macias, Maximiliano,Arndtsen, Bruce A.
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supporting information
p. 10140 - 10144
(2018/08/23)
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- PREPARATION OF HALIDE PRODUCTS
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The invention is directed to a method for the preparation of an acyl or alkyl halide, comprising, respectively, reacting a carboxylic acid or an alcohol with a halogenation agent in the presence of a base, wherein the reaction is at least partially carrie
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Page/Page column 9
(2017/11/04)
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- Tankyrase inhibitor
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The invention belongs to the technical field of medicine and specifically relates to a tankyrase inhibitor represented as a general formula (I) and pharmaceutically acceptable salts, esters, solvated compounds or stereisomers of the tankyrase inhibitor, wherein R1, R2, X1, X2, Y1, Y2, Y3, Y4, Z, L, n and A are defined as in the description. The invention also relates to preparation methods of the compounds, pharmaceutical preparations and pharmaceutical compositions containing the compounds, and applications of the compounds and the pharmaceutically acceptable salts, esters, solvated compounds or the stereoisomers of the compounds in preparing medicines of curing and/or preventing cancers and related diseases which are mediated by tankyrase.
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Paragraph 0238-0241; 0263-0265; 0328-0330
(2018/02/04)
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- Phosphinito palladium(ii) complexes as catalysts for the synthesis of 1,3-enynes, aromatic alkynes and ynones
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An air-stable phosphinito palladium(ii) complex (Ph1-Phoxide) has been found to be an efficient catalyst in the formation of C-C bonds. The coupling of terminal alkynes formed gem-1,3-enynes as the only reaction products. Aromatic alkynes can be synthesized from the coupling of terminal alkynes and haloaromatic compounds (Sonogashira coupling). The phosphinito palladium(ii) complex also catalyses the coupling between acyl chlorides and terminal alkynes (Sonogashira coupling), furnishing ynones in excellent yields.
- Islas,Cárdenas,Gavi?o,García-Ríos,Lomas-Romero,Morales-Serna
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p. 9780 - 9789
(2017/02/15)
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- METHOD FOR PREPARATION OF CARBOXYLIC ACID CHLORIDES FROM METHYL KETONES WITH TWO REAGENTS
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The invention discloses a method for the preparation of carboxylic acid chlorides starting from methyl ketones with a sulfur chloride and a chlorinating reagent.
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Page/Page column 33
(2017/01/26)
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- Mesomorphism dependence on central bridge (-COO-CH2-) and terminal end group (-Br)
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A novel series of liquid crystalline (LC) ester materials has been synthesized and studied with a view to understanding the effects of molecular structure on LC behavior. The homologous series of eleven members is entirely enantiotropically smectogenic without exhibition of a nematic phase. Transition temperatures and the texture of smectic phase was determined by an optical polarizing microscope equipped with a heating stage (POM). Transition curves (Cr-Sm and Sm-I) showing phase behavior in a phase diagram behave in a normal manner. Textures of smectic phase are focal conic fan shaped of the type Smectic-A or Smectic-C. An odd-even effect is exhibited by the Sm-I transition curve. The average thermal stability for smectic is 91.2°C and the mesogenic phase length ranges between 3.6°C and 39.3°C. Thus, the novel smectogenic homologous series is a middle-ordered melting type whose LC phase is relatively middle ordered. The LC properties of the present series are compared with a structurally similar homologous series. Analytical and spectral data support the molecular structures.
- Marathe, Rajesh B.,Doshi
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p. 122 - 131
(2016/02/19)
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- Mesomorphism of azo-esters and chalcone-esters
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AOne chalcone-ester homologous series of mesogens α-4-[4/-n-alkoxybenzoyloxy phenyl β-4//methoxy benzoyl ethylenes (A) and one azo-ester homologous series of mesogens p-(p/-n-alkoxybenzoyloxy) phenyl azo-p//-methoxy benzene (B) being structurally similar are discussed. Both series (A) and (B) differ in respect of central bridges linking two phenyl rings. Mesomorphic properties start from 6th and 1st member of series (A) and (B) respectively. In series (A), 6th to 12th members show both smectogenic and nematogenic properties, and the 14th and 16th members show only nematogenic property. While in series (B), 1st to 10th members show nematogenic properties, 11th member shows both smectogenic and nematogenic properties, while 12th member shows only smectogenic property. Thermal stability of series (A) is relatively high as compared to series (B). Transition temperatures are observed through hot stage polarizing microscope by the miscibility method. Analytical data support the structure of molecules. Textures of series (A) in nematic are threaded and Schlieren in SmecticSmectic A type, while that of series (B) in nematic are threaded in SmecticSmectic A and smectic C.
- Jain,Sharma, Vinay S.,Chauhan,Patel
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p. 102 - 111
(2016/07/14)
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- Mesomorphism dependence on lateral substitution and central bridge
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A novel ester homologous series was synthesized and studied with a view to understanding and establishing the effects of molecular structure on liquid crystal properties with a common laterally substituted-OCH3 group and changing terminal groups. The novel series consists of twelve members. The C1 to C3 members are not liquid crystals and the rest of the members C4 to C16 are smectogenic without exhibition of nematic character. Textures of smectic phase are focal conic fan shaped of the type A or C. The transition temperatures and textures of smectic mesophases were observed through hot stage polarizing microscopy (POM). The transition curves (Cr-I or Cr-M and Sm-I) behaved in normal manner. Analytical and spectral data support the molecular structures. Average thermal stability for smectic is 77.25°C and smectogenic mesophase ranges from 15°C to 33°C. Liquid crystal properties of the present series are compared with structurally similar homologous series. Thus, the series is smectogenic only with three homologs nonmesogenic.
- Vadodaria,Ladva,Doshi,Travadi
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p. 103 - 111
(2016/02/19)
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- Study of mesomorphism and its relation to molecular structure with special reference to central bridges viz. -COO- and -CH=CH-COO- of the homologous series
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Two ester homologous series of mesogens, viz., Methyl-p-(p′-n-alkoxy benzoyloxy) cinnamates (X) and Methyl-p-(p′-n-alkoxy cinnamoyloxy) cinnamates (Y) being structurally similar are discussed. Both (X) and (Y) differ in respect of central bridges linking two phenyl rings. Only enantiotropic nematogenic character is observed without exhibition of any smectic character by all members of series (X) and (Y). Thermal stability of series (X) is relatively low as compared to (Y), but nematogenic mesophase lengths are of reverse order. Solid-nematic/solid-isotropic and nematic-isotropic transition curves in the phase diagrams behave in normal manner.
- Sharma,Solanki,Patel,Patel
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p. 137 - 145
(2016/03/01)
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- Mesomorphism dependence on molecular rigidity with reference to -CH=CH- unit of central bridge
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A novel ester homologous series of rich mesomorphism and low temperatures with unexpected phase behaviors of eleven homologues was synthesized and studied with a view to understanding and establishing the relation between mesomorphic behaviour and the molecular structure of a series 4-(4′-n-alkoxybenzoyloxy)-4″-chlorobenzyl cinnamates. All the members of the novel series are enantiotropically smectogenic and the octyloxy (C8) to hexadecyloxy (C16) homologues are enantiotropically nematogenic, in addition to smectogenic. Odd-even effect is observed for Sm-I/Sm-N transition curve but it is absent for N-I transition curve. Textures of nematic phase are threaded or Schlieren and that of the smectic phase are fan shaped or batonates of smectic-A type phase or Smectic-C type for C16 homologues as judged directly from a heating stage of an optical polarizing microscopy. Analytical and spectral data confirmed the molecular structures of novel homologues. Mesomorphic properties of present series are compared with the structurally similar other known series. The average smectic and nematic thermal stabilities are 92.78°C and 100.8°C, respectively. Mesophase length minimum to maximum for smectic and nematic are 21.0°C to 31.1°C and 8.4°C to 42.6°C respectively. Thus, the present novel series is partly nematogenic and fully smectogenic with considerable degree of mesomorphism and low melting type.
- Marathe,Doshi
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- Mesomorphism dependence on tail group
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A chalconyl homologous novel series of thermotropic liquid crystals (LC) have been synthesized and studied with a view to understand and establish the effects of molecular structure on LC properties in thermotropic behaviors. Homologous series RO-C6H4-COO-C6H4-CO-CH=CH-C6H4-OC14H29 consists of 13 homologs (C1–C18), C1–C6 homologs are nonliquid crystals and the rest of the homologs are enantiotropically nematogenic without exhibition of smectic property. Transition temperatures and the textures of the nematic phase were determined by an optical polarizing microscopy, equipped with a heating stage. Texture of a nematic phase are threaded or schlieren. The Spectral and analytical data confirms the molecular structures of homologs. Thermal stability for nematic is 123.0°C and its mesogenicphaselength ranges between 13°C and 34°C. Cr-N/I and N-I transition curves behaved in normal manner except C14 homolog which shows negligible abnormality for N-I transition temperature or curve with exhibition of odd-even effect. Some LC properties are compared with the structurally similar homologous series. Thus, present homologous series is nematogenic and middle ordered melting type.
- Jain,Patel
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p. 121 - 129
(2016/07/14)
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- Study of novel thermotropic liquid crystals with lateral nitro substituent
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In this article, we report synthesis and characterization of a novel thermotropic liquid crystals, namely, 4-bromo-[3′-nitro-4′(4″-n-alkoxybenzoyloxy)] phenyl azobenzenes. The first member of a homologous series is nonmesogenic in nature. The n-ethyl to n-decyl homologues exhibit enantiotropic nematic mesophases, while the n-dodecylton -hexadecyl homologues exhibit only smectic mesophases. The synthesized compounds were characterized by a combination of elemental analysis and standard spectroscopic methods. The mesogenic behavior of present series is explained by comparing each homologue of the related mesogenic series. The impact of the lateral nitro group on mesomorphism is also discussed.
- Dixit,Intwala
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