scholarly journals Dimethyl 4,5-dichlorophthalate

IUCrData ◽  
2021 ◽  
Vol 6 (10) ◽  
Author(s):  
Daniel D. Hickstein ◽  
Eric W. Reinheimer ◽  
Adam R. Johnson ◽  
Daniel J. O'Leary
Keyword(s):  
Methyl Ester ◽  
Aromatic Ring ◽  
Electrostatic Interactions ◽  
Structural Integrity ◽  
Carbonyl Carbon Atom ◽  
Carbonyl Carbon ◽  
Precursor Molecule ◽  
Ester Moiety ◽  
Crystal Structural ◽  
Metathesis Catalysts

While endeavoring to synthesize new chlorinated ligands for ruthenium-based metathesis catalysts, the title compound dimethyl 4,5-dichlorophthalate, C10H8Cl2O4, was prepared from commercially available 4,5-dichlorophthalic acid in ∼77% yield. The title molecule, which also finds utility as a precursor molecule for the synthesis of drugs used in the treatment of Alzheimer's disease, shows one carbonyl-containing methyl ester moiety lying nearly co-planar with the chlorine-derivatized aromatic ring while the second methyl ester shows a significant deviation of 101.05 (12)° from the least-squares plane of the aromatic ring. Within the crystal, structural integrity is maintained by the concerted effects of electrostatic interactions involving the electron-deficient carbonyl carbon atom and the electron-rich aromatic ring along the a-axis direction and C—H...O hydrogen bonds between neighboring molecules parallel to b.

scholarly journals Ester Dance Reaction on the Aromatic Ring

2019 ◽  
Author(s):  
Kaoru Matsushita ◽  
Ryosuke Takise ◽  
Kei Muto ◽  
Junichiro Yamaguchi
Keyword(s):  
Carbon Atom ◽  
Aromatic Ring ◽  
Functional Group ◽  
State Of The Art ◽  
Palladium Catalysis ◽  
Ester Group ◽  
Halogen Atoms ◽  
Ester Moiety ◽  
Rearrangement Reactions ◽  
Halogen Dance Reaction

Aromatic rearrangement reactions are useful tools in the organic chemist’s toolbox when generating uncommon substitution patterns. However, it is difficult to precisely translocate a functional group in (hetero)arene systems, with the exception of halogen atoms in a halogen dance reaction. Herein, we describe an unprecedented “ester dance” reaction: a predictable translocation of an ester group from one carbon atom to another on an aromatic ring. Specifically, a phenyl carboxylate substituent can be shifted from one carbon to an adjacent carbon on a (hetero)aromatic ring under palladium catalysis to often give a thermodynamically favored, regioisomeric product with modest to good conversions. The obtained ester moiety can be further converted to various aromatic derivatives through the use of classic as well as state-of-the-art transformations including an amidation, acylations and decarbonylative couplings.

Argon Matrix Infrared Spectroscopic Evidence for the Generation of Pentatetraenone by Flash Pyrolysis of Suitable Precursors

1988 ◽  
Vol 41 (2) ◽  
pp. 225 ◽  
Author(s):  
RFC Brown ◽  
KJ Coulston ◽  
FW Eastwood ◽  
MJ Irvine ◽  
ADE Pullin
Keyword(s):  
Carbon Atom ◽  
Infrared Spectra ◽  
Spectral Region ◽  
Narrow Band ◽  
Broad Band ◽  
Carbonyl Carbon Atom ◽  
Carbonyl Carbon ◽  
Argon Matrix ◽  
Spectroscopic Evidence ◽  
Argon Mixture

Five compounds were investigated as precursors for the pyrolytic generation of pentatetraenone, H2C=C=C=C=C=O. These were (1)-(4): 3- ethenylidenebicyclo [2.2.1]hept-5-ene with the following 2,2 substituents : H, COOCOCF3 (1); H, 13COOCOCF3 (1′); (COOCOCF3)2 (2); (COO)2C(CH3)(OCH3) (3); (COO)2Si(CH3)2 (4) and 5-(3′- methylenebicyclo [2.2.1]hept-5′-en-2′-ylidene)-2,2-dimethyl-1,3-dioxan-4,6-dione (5). The five precursors were pyrolysed in a stream of argon at temperatures in the range 350-725°C and the pyrolysate -argon mixture condensed on a CsI plate at c. 10 K. Infrared spectra were obtained between 4000 and 250 cm-1. All five precursors gave two strong bands in the spectral region 2070-2250 cm-1, possibly attributable to pentatetraenone. At lower pyrolytic temperatures the more intense of the two bands was a broad band centred at c. 2128 cm-1 [precursors (1)- (4)] or at c. 2094 cm-1 [precursor (5)]. At higher pyrolytic temperatures these bands were diminished in intensity and replaced by a narrow band at 2207 cm-1 for all five precursors. Bands due to the expected other products for each pyrolysis reaction to form pentatetraenone were observed. H2C413CO ( pentatetraenone substituted by 13C at the carbonyl carbon atom) was prepared by pyrolysis of precursor (1′). We assign the broad bands at c. 2128 cm-1 [precursors (1)-(4)] and at c. 2094 [precursor (5)] to incompletely pyrolysed precursor in which cyclopentadiene has been retained but decomposition in the rest of the molecule has resulted in formation of a =C=C=O group. Bands at 2207, 2068 and 1726 cm-1 we assign to v2-v4 of pentatetraenone. Corresponding bands at 2168, 2056 and 1720 cm-1 are observed in the spectrum of H2C413CO.

scholarly journals Methyl 3,5-bis(cyclohexylmethoxy)benzoate

2014 ◽  
Vol 70 (4) ◽  
pp. o400-o401 ◽  
Author(s):  
Peter W. R. Corfield ◽  
Michele L. Paccagnini ◽  
Amy M. Balija
Keyword(s):  
Methyl Ester ◽  
Hydrogen Bonds ◽  
Aromatic Ring ◽  
Title Compound ◽  
Ester Group ◽  
Interplanar Distance ◽  
Compound C ◽  
The Mean

In the title compound, C22H32O4, the atoms of the methyl ester group and the alkoxy O atoms are all coplanar with the central aromatic ring, with an r.m.s. deviation of 0.008 Å. Bonds to the methylene and cyclohexyl groups are also very close to this plane, so that the molecule is essentially flat, apart from the cyclohexyl groups. The mean planes through the cyclohexyl groups are tilted by 30.08 (9) and 36.14 (7)° with respect to the central aromatic ring. In the crystal, pairs of molecules linked by C—H...O hydrogen bonds form planar units which are stacked along theaaxis, with an average interplanar distance of 3.549 (2) Å. Stacking appears to be stabilized by further weak C—H...O hydrogen bonds.

The triterpenes of Emmenospermum pancherianum

1980 ◽  
Vol 33 (9) ◽  
pp. 2071 ◽  
Author(s):  
GV Baddeley ◽  
JJH Simes ◽  
T Ai
Keyword(s):  
Methyl Ester ◽  
Acid Hydrolysis ◽  
Aromatic Ring ◽  
Spectroscopic Analysis ◽  
Dioic Acid

The free triterpenes identified as constituents of Emmenospermum pancherianum Baill. are ceanothic acid (wood), betulic acid (bark), and the new triterpene, 18α,24-dihydroxy-A(1)-norlupa-2,20(29)-diene-27,28- dioic acid 28-methyl ester 27,18α-lactone (1a) (bark); the structure of the last has been determined by spectroscopic analysis. Both wood and bark contained saponin which in each case on acid hydrolysis gave ebelin lactone, and two new sapogenins, 24,25-dihydroebelin lactone (9a)and the tetracarbocyclic triterpenoid (10a) possessing an aromatic ring D; all three sapogenins are secondary sapogenins. The primary sapogenins jujubogenin (11a) and dihydrojujubogenin (12a)have been obtained by degradation of the wood saponin, and dihydrojujubogenin has been shown to be the precursor of (9a) and (10a).

Aril Azines. II. Hydrogenation of p-Tolil Monoazine

1975 ◽  
Vol 53 (5) ◽  
pp. 748-752 ◽  
Author(s):  
Peter Yates ◽  
E. M. Levi
Keyword(s):  
Hydrogen Atom ◽  
Carbon Atom ◽  
Sodium Borohydride ◽  
Sodium Methoxide ◽  
Major Product ◽  
Lead Tetraacetate ◽  
Ring Closure ◽  
Carbonyl Carbon Atom ◽  
Carbonyl Carbon ◽  
Independent Synthesis

Hydrogenation of p-tolil monoazine (1b) over palladium-on-charcoal gives as the major product 4,5-dihydro-5-(p-toluyl)-3,4,5-tri-(p-tolyl)-1H-pyrazol-4-ol (2b), which has previously been obtained by treatment of 1b with sodium methoxide. Several minor products are formed, which include p-tolualdehyde, p-toluic acid, and p-toluamide, p-tolunitrile, p-tolualazine, and 3,4,5-tri-(p-tolyl)-4H-pyrazo-4-ol (9). The structure of the last compound, which is also formed on reduction of 1b with sodium borohydride, was established by its independent synthesis from 1,2,3-tri-(p-tolyl)-1,3-propanedione by oxidation with lead tetraacetate followed by treatment with hydrazine. It is suggested that 2b arises via reduction of a C=N bond of 1b and aldol ring closure. The minor hydrogenation products are of interest in that their formation involves C—C hydrogenolysis; it is suggested that this is initiated by addition of a hydrogen atom to a carbonyl carbon atom of 1b.

scholarly journals Modified polysulphone membranes: 1. Pervaporation of water/alcohol mixtures through modified polysulphone membranes having methyl ester moiety

Polymer ◽  
1992 ◽  
Vol 33 (22) ◽  
pp. 4805-4813 ◽  
Author(s):  
Masakazu Yoshikawa ◽  
Hirohisa Hara ◽  
Masataka Tanigaki ◽  
Michael Guiver ◽  
Takeshi Matsuura
Keyword(s):  
Methyl Ester ◽  
Ester Moiety ◽  
Alcohol Mixtures ◽  
Water Alcohol

scholarly journals SYNTHESIS OF SOME CINNAMIC ACID DERIVATIVES: EFFECT OF GROUPS ATTACHED ON AROMATIC RING TO THE REACTIVITY OF BENZALDEHYDE

2010 ◽  
Vol 8 (2) ◽  
pp. 226-230
Author(s):  
Marcellino Rudyanto ◽  
Lanny Hartanti
Keyword(s):  
Aromatic Ring ◽  
Malonic Acid ◽  
Cinnamic Acid ◽  
Knoevenagel Reaction ◽  
Carbonyl Carbon ◽  
Cinnamic Acid Derivatives ◽  
Alkoxy Groups

Synthesis of cinnamic acid and its six derivatives has been done by employing Knoevenagel reaction. Benzaldehyde, 4-butylbenzaldehyde, 4-t-butylbenzaldehyde, 4-butoxybenzaldehyde, 4-phenylbenzaldehyde, 5-bromo-2,4-dimethoxybenzaldehyde, and 5-bromo-2,3-dimethoxybenzaldehyde were reacted with malonic acid in pyridine – piperidine to give cinnamic acid (85,3%), 4-butylcinnamic acid (69,3%), 4-t-butylcinnamic acid (77,7%), 4-butoxycinnamic acid (64,5%), 4-phenylcinnamic acid (65,5%), 5-bromo-2,4-dimethoxycinnamic acid (53,2%) and 5-bromo-2,4-dimethoxycinnamic acid (57,2%), respectively. It was disclosed that 4-alkyl, 4-alkoxy, 4-aryl, dan 2-alkoxy groups decrease the reactivity of carbonyl carbon of benzaldehyde.   Keywords: cinnamic acid, cinnamic acid derivatives, Knoevenagel reaction

scholarly journals Crystal structure of an orthomyxovirus matrix protein reveals mechanisms for self-polymerization and membrane association

2017 ◽  
Vol 114 (32) ◽  
pp. 8550-8555 ◽  
Author(s):  
Wenting Zhang ◽  
Wenjie Zheng ◽  
Yukimatsu Toh ◽  
Miguel A. Betancourt-Solis ◽  
Jiagang Tu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Crystal Lattice ◽  
Influenza A Virus ◽  
Nuclear Export ◽  
Influenza A ◽  
Electrostatic Interactions ◽  
Matrix Protein ◽  
Structural Integrity ◽  
Viral Envelope ◽  
Protein Layer

Many enveloped viruses encode a matrix protein. In the influenza A virus, the matrix protein M1 polymerizes into a rigid protein layer underneath the viral envelope to help enforce the shape and structural integrity of intact viruses. The influenza virus M1 is also known to mediate virus budding as well as the nuclear export of the viral nucleocapsids and their subsequent packaging into nascent viral particles. Despite extensive studies on the influenza A virus M1 (FLUA-M1), only crystal structures of its N-terminal domain are available. Here we report the crystal structure of the full-length M1 from another orthomyxovirus that infects fish, the infectious salmon anemia virus (ISAV). The structure of ISAV-M1 assumes the shape of an elbow, with its N domain closely resembling that of the FLUA-M1. The C domain, which is connected to the N domain through a flexible linker, is made of four α-helices packed as a tight bundle. In the crystal, ISAV-M1 monomers form infinite 2D arrays with a network of interactions involving both the N and C domains. Results from liposome flotation assays indicated that ISAV-M1 binds membrane via electrostatic interactions that are primarily mediated by a positively charged surface loop from the N domain. Cryoelectron tomography reconstruction of intact ISA virions identified a matrix protein layer adjacent to the inner leaflet of the viral membrane. The physical dimensions of the virion-associated matrix layer are consistent with the 2D ISAV-M1 crystal lattice, suggesting that the crystal lattice is a valid model for studying M1–M1, M1–membrane, and M1–RNP interactions in the virion.

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