10031-82-0Relevant articles and documents
Synthesis of aromatic aldehydes by oxidative hydroxymethylation
Branytska, Oiena,Neumann, Ronny
, p. 1575 - 1576 (2004)
A new high yield method for the synthesis of aromatic aldehydes has been developed. The procedure is based on an acid catalyzed hydroxymethylation of an arene substrate by paraformaldehyde with concurrent selective oxidation of the intermediate aromatic carbinol by 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) to the aldehyde product.
Tuning the mesomorphic properties of nonisomeric chalconyl-ester bases homologous series: The effect of tail group
Sharma, Vinay S.,Patel
, p. 40 - 51 (2017)
The mesomorphic properties of nonlinear chalconyl ester homologous series can be tuned in a predictable fashion with tail groups (-OC16H33) substituents on the terminal side. Novel series consisted thirteen members (C1–C8, C10, C12, C14, C16, C18). C1 to C5 homologues are nonliquid crystal, C6 to C14 homologues shows nematic mesophase enantiotropically, while C16, C18 exhibits smectic as well nematic properties. The texture of the nematic mesophase is of fan shaped, schlieren and nematic droplets type. All these compounds were characterized by elemental analyses and spectroscopic techniques such as [FTIR] and 1H Nuclear magnetic resonance [NMR] spectroscopy. The mesomorphic properties of these compoundswere observed by optical polarized light microscopy (POM) and differential scanning calorimetry (DSC).
Mesomorphism dependence on molecular rigidity and flexibility
Ranchchh, Avani R.,Bhoya
, p. 43 - 51 (2018)
A novel homologous series of liquid crystalline properties is synthesized and studied with a view to understand the effect of molecular structure on its thermotropic properties. Novel homologous series consisted of thirteen homologs. All the homologs are enantiotropically smectogenic with absence of nematic property even in the monotropic condition. Textures of the homologs as observed through an optical hot stage polarizing microscopy. The mesophase temperature range vary minimum from 6.0°C to a maximum 37.0°C at the methyloxy and propyloxy derivatives of a series respectively with its thermal stability (Sm–I) 127.0°C. Transition curves of a phase diagram behaved in normal manner. Odd–even effect is observed for Sm–I transition curve.
Transition metal-free catalytic oxidation of aromatic alcohols with molecular oxygen in the presence of a catalytic amount of N-bromosuccinimide
Tong, Xinli,Sun, Yongfa,Yan, Yongtao,Luo, Xuan,Liu, Jinbiao,Wu, Zhidong
, p. 1 - 6 (2014)
A highly efficient N-bromosuccinimide (NBS)-mediated transition metal-free catalytic system has developed for the efficient aerobic oxidation of aromatic alcohols. Various aromatic alcohols are successfully oxidized to the corresponding aldehydes or keton
Mesomorphism and flexibility of alkyl chains in chalcone esters
Muniya,Patel
, p. 95 - 102 (2016)
A novel homologous series of chalconyl ester liquid crystals (LCs): RO?C6H4–CH:CH–COO?C6H4–CO?CH:CH?C6H4–OC10H21 (n) (para) has been synthesized and studied with a view to understanding and establishing the relationship between molecular structure and LC properties with reference to flexibility of the terminal chain. The novel series consists of eleven homologs (C1–C16). The C1 and C2 homologs are nonliquid crystals and the rest of the homologs (C3–C16) are enantiotropic nematic without exhibition of smectic mesophase. Transition and melting temperatures were determined by an optical polarizing microscope equipped with a heating stage. Textures of nematic phases are threaded or Schlieren. Cr-N/I transition curve adopts a zigzag path in a normal manner with overall descending behaviors. The N-I transition curve exhibits a sharp and shorter odd-even effect from C3 to C6 and it diminishes from and beyond C6 for higher homologs of longer n-alkyl chain (R) in more or less or negligible deviating manner from normal descending tendency. Thermal stability for the nematic is 116.4°C and mesophase length ranges from 19°C to 67°C at the C3 and C12 homolog respectively. The LC properties of present novel series are compared with structurally similar analogous series to derive group efficiency order.
A Convenient Oxidation of Benzylic Methyl, Methylene, and Methine Groups with Potassium Permanganate/Triethylamine Reagent
Li, Wen-Shan,Liu, Lilian Kao
, p. 293 - 295 (1989)
A useful and versatile procedure for benzylic oxidations with potassium permanganate/triethylamine has been developed.The methyl, methylene and methine groups are oxidized in good to excellent yields to benzylic aldehydes and ketones and to tertiary benzyl alcohols, respectively.This procedure can easily be carried out in conventional organic solvents without using any phase-transfer or supported catalysts.
Mesomorphism dependence of a terminal or lateral alkoxy group
Solanki, Ravindra,Patel
, p. 50 - 57 (2016)
A novel homologous series of thermotropic mesomorphs has been synthesized and studied with a view to understanding and establishing the effect of molecular structure on mesomorphic properties with reference to rigidity and flexibility of the homologues series: RO-C6H4-CH?CH-CO-C6H4-OC18H37(n). The novel homologous series comprises 13 novel homologues (C1 to C18), from which 11 homologues are enantiotropically mesogenic (C3 to C18). Smectogenic mesophase commences from C7 homologue, and nematogenic mesophase is exhibited by C3 to C18 homologues in enantiotropic manner. Thus, C7 to C18 homologues are enantiotropically smectogenic plus nematogenic. Textures of smectic phase are of the type A or C, and that of nematic phase are threaded or Schlieren as confirmed through an optical polarizing microscope equipped with a heating stage. Transition curve of a phase diagram behaved in a normal manner except N-I transition curve, which shows minor deviating trend (C12 to C18) from expected normal behavior. An odd-even effect is exhibited by N-I and Sm-N transition curves. Analytical, spectral, and thermal data confirm the molecular structures of novel homologues. Thermal stabilities for smectic and nematic are 52.7°C and 66.6°C, respectively, whose total mesophase lengths range from 12.0°C to 28.0°C. Thus, novel series of chalcones is a low melting series whose mesogenic transition temperatures vary between 38.0 and 86.0°C.
Mild and selective hydrozirconation of amides to aldehydes using Cp 2Zr(H)Cl: Scope and mechanistic insight
Spletstoser, Jared T.,White, Jonathan M.,Tunoori, Ashok Rao,Georg, Gunda I.
, p. 3408 - 3419 (2007)
An investigation of the use of Cp2Zr(H)Cl (Schwartz's reagent) to reduce a variety of amides to the corresponding aldehydes under very mild reaction conditions and in high yields is reported. A range of tertiary amides, including Weinreb's amides, can be converted directly to the corresponding aldehydes with remarkable chemoselectivity. Primary and secondary amides proved to be viable substrates for reduction as well, although the yields were somewhat diminished as compared to the corresponding tertiary amides. Results from NMR experiments suggested the presence of a stable, 18-electron zirconacycle intermediate that presumably affords the aldehyde upon water or silica gel workup. A series of competition experiments revealed a preference of the reagent for substrates in which the lone pair of the nitrogen is electron releasing and thus more delocalized across the amide bond by resonance. This trend accounts for the observed excellent selectivity for tertiary amides versus esters. Experiments regarding the solvent dependence of the reaction suggested a kinetic profile similar to that postulated for the hydrozirconation of alkenes and alkynes. Addition of p-anisidine to the reaction intermediate resulted in the formation of the corresponding imine mimicking the addition of water that forms the aldehyde.
N-methyl morpholine chlorochromate: An efficient reagent for oxidation of primary and secondary alcohols to carbonyl compounds
Chandrappa,Sadashiva,Rangappa
, p. 2638 - 2645 (2008)
Instantaneous generation of N-methyl morpholine chlorochromate (NMMCC) is an efficient reagent for oxidation of primary and secondary alcohols to the corresponding carbonyl compounds. The comparison of reaction time and product yield was studied with novel NMMCC and other chlorochromate reagents and shows that the presented method requires less reaction time with good yield at laboratory temperature. The synthesis of reagent, formation of toxic and hazardous chromylchloride have been avoided, and also use of NMMCC under microwave irradiation for oxidation leads to fast reaction time and success of the strategy. Copyright Taylor & Francis Group, LLC.
Mesomorphism of Novel Symmetric Dimers with Changing Alkoxy Terminal End Group
Bhola,Maheta,Bhoya
, p. 129 - 138 (2015)
A novel homologous series of symmetric dimers has been synthesized. It consists of thirteen (C1 to C8, C10, C12, C14, C16 and C18) dimer ester derivatives from trans cinnamic acid with pyrocatechol. Mesomorphic property commences from C7 homologue as smectic. C1 to C6 members of the series are nonmesomorphic. C7 is monotropic smectic and the rest of the homologues from C8 to C18 are enantiotropic smectic. The nematic mesophase is totally absent. Textures and transition temperatures of the homologues are determined by an optical polarizing microscope equipped with a heating stage. IR, 1H NMR spectra, mass spectra, and differential scanning calorimetry of some members is included. The spectroscopic analyses support the molecular structures. Mesomorphic properties of the novel symmetric dimer series are compared with structurally similar series. The novel series is partly nonmesomorphic and predominantly smectogenic with textures of the A or C type, without the exhibition of the nematic phase.
