100-07-2Relevant articles and documents
Mild hydrolysis or alcoholysis of amides. Ti(IV) catalyzed conversion of primary carboxamides to carboxylic acids or esters
Fisher,Caroon,Stabler,Lundberg,Zaidi,Sorensen,Sparacino,Muchowski
, p. 142 - 145 (1994)
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.
Mesomorphism dependence on positional substitution of same polar group on same phenyl ring in isomeric homologous series
Prajapati,Doshi
, p. 62 - 71 (2015)
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.
Facile synthesis of acacetin-7-O-β-d-galactopyranoside
Zacharia, James T.,Hayashi, Masahiko
, p. 91 - 94 (2012)
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.
Mesomorphism dependence on molecular flexibility
Travadi,Vadodaria,Ladva,Doshi
, p. 69 - 78 (2016)
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.
The synthesis and mesomorphic properties of a novel homologous series: α-4-[4′-n-alkoxy benzoyloxy] benzoyl-β-2″-nitro phenyl ethylenes
Chauhan,Doshi
, p. 92 - 100 (2013)
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.
Reaction of sec amides with metal hydride. II. Reaction of acid chlorides with sodium acetanilidoborohydride
Kikugawa,Yokoyama
, p. 1939 - 1943 (1976)
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Study of Mesomorphism Through a Novel Homologous Series and Its Relation to Molecular Structure
Doshi,Chauhan
, p. 66 - 74 (2015)
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.
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
Patel,Prajapati,Doshi
, p. 51 - 58 (2016)
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.
Dependence of thermotropic mesomorphism on molecular flexibility of changing tail group
Solanki, Ravindra,Sharma, Vinay,Patel, Roshan
, p. 107 - 115 (2016)
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.
Synthesis and evaluation of liquid crystalline properties of a novel homologous series: α-3-[4′-n-alkoxy benzoyloxy] phenyl-β- 4″-nitro benzoyl ethylenes
Suthar,Doshi, Ankita A.,Doshi
, p. 75 - 83 (2013)
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.
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
Badjic,Kostic
, p. 408 - 418 (2001)
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
Dependence of mesomorphism on tail group in combination with a lateral methoxy group
Travadi,Vadodaria,Ladva,Doshi
, p. 63 - 71 (2016)
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.
Dependence of thermotropic mesomorphism on flexible tail group
Patel, Priya K.,Shah
, p. 130 - 138 (2016)
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.
SALICYLOYLASPARTATE AS AN ENDOGENOUS COMPONENT IN THE LEAVES OF PHASEOLUS VULGARIS
Bourne, David J.,Barrow, Kevin D.,Milborrow, B. V.
, p. 4041 - 4044 (1991)
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.
Synthesis of novel ester series and study of its mesomorphism dependence on terminal end group with lateral-OCH3 group
Vadodaria,Ladva,Doshi,Travadi
, p. 59 - 68 (2016)
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.
Mesomorphism Dependence of Chalconyl Derivatives on Position of -CH=CH- Unit
Rakhasia,Bhola,Bhoya
, p. 81 - 89 (2016)
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.
Study of Novel Symmetrical Liquid Crystalline Ester Dimers
Kotadiya,Bhoya
, p. 19 - 27 (2015)
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.
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Denney
, p. 590 (1956)
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Study of Liquid Crystal Behavior and Dependence on Additional Central Bridge of Ester Homologous Series
Marathe, Rajesh B.,Doshi
, p. 74 - 82 (2015)
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.
Dependence of liquid crystallinity on molecular rigidity
Rakhasia,Bhoya
, p. 55 - 62 (2016)
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.
PCl3-mediated transesterification and aminolysis of tert-butyl esters via acid chloride formation
Wu, Xiaofang,Zhou, Lei,Li, Fangshao,Xiao, Jing
, p. 491 - 497 (2021)
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.
A novel homologous series of thermotropic mesogens of ethylene derivatives: α-4-[4′-n-Alkoxy Benzoyloxy] phenyl β-4″ methoxy benzoyl ethylenes
Chauhan,Doshi
, p. 12 - 19 (2013)
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.
One-step Conversion of Amides and Esters to Acid Chlorides with PCl3
Li, Fangshao,Wu, Xiaofang,Guo, Fengzhe,Tang, Zi-Long,Xiao, Jing
, p. 4314 - 4317 (2021)
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.
Exploring unsymmetrical dyads as efficient inhibitors against the insect β-N-acetyl-d-hexosaminidase OfHex2
Chen, Qi,Guo, Peng,Xu, Lin,Liu, Tian,Qian, Xuhong,Yang, Qing
, p. 152 - 162 (2014)
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
Mesomorphism Dependence on Molecular Structure
Travadi,Vadodaria,Ladva,Doshi
, p. 21 - 30 (2016)
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.
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
Khanum, Shaukath Ara,Martiz, Reshma Mary,Ramu, Ramith,Ranganatha, V. Lakshmi,V, Rashmi
, (2021/12/30)
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
3-(3'-hydroxybutyl) isobenzofuran-1(3H)-ketone derivative as well as composition, preparation method and application thereof
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Paragraph 0071; 0085; 0088; 0091; 0096; 0098-0099, (2021/05/15)
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
Xylochemical synthesis and biological evaluation of shancigusin c and bletistrin g
Efferth, Thomas,Geske, Leander,Kauhl, Ulrich,Opatz, Till,Saeed, Mohamed E. M.,Schüffler, Anja,Thines, Eckhard
supporting information, (2021/06/16)
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.
