- REARRANGEMENT OF DIMETHYLPHENYLACYLATES USING ZEOLITES
-
The present invention relates to a Fries rearrangement of specific dimethylphenylacylates to form the desired respective hydroxyaryl ketones having two methyl groups bound to the aromatic ring. It has been found that the process is surprisingly very specific in view of the number and position of the methyl group(s) bound to the aromatic ring.
- -
-
Page/Page column 9-10; 12
(2021/08/14)
-
- Synthesis and anti-inflammatory activity of 2-oxo-2H-chromenyl and 2H-chromenyl-5-oxo-2,5-dihydrofuran-3-carboxylates
-
Cycloaddition reaction of 4-chloro-2-oxo-2H-chromene-3-carbaldehydes (3a-g) and 4-chloro-2H-chromene-3-carbaldehydes (7a-h) with activated alkynes (4a-b) provided the 2-oxo-2H-chromenyl-5-oxo-2,5-dihydrofuran-3-carboxylates (5a-n) and 2H-chromenyl-5-oxo-2,5-dihydrofuran-3-carboxylates (8a-p). All the prepared compounds were screened for anti-inflammatory activity. In vitro anti-inflammatory activity data demonstrated that the compounds 5g, 5i, 5k-l and 8f are effective among the tested compounds against TNF-α (1.108 ± 0.002, 0.423 ± 0.022, 0.047 ± 0.001, 0.070 ± 0.002 and 0.142 ± 0.001 μM) in comparison with standard compound Prednisolone (0.033 ± 0.002 μM). Based on in vitro results, three compounds (5i, 5k and 8f) have been selected for in vivo experiments and these compounds are identified as better compounds with respect to anti-inflammatory activity in LPS induced mice model. Compound 5i was identified as potent and showed significant reduction in TNF-α and IL-6.
- Bhimapaka, China Raju,Karri, Shailaja,Kuncha, Madhusudana,Kurma, Siva Hariprasad,Sistla, Ramakrishna
-
-
- Substrate substitution effects in the Fries rearrangement of aryl esters over zeolite catalysts
-
The catalytic transformation of aryl esters to hydroxyacetophenones via Fries rearrangement over solid acids is of interest to avoid the use of corrosive and toxic Lewis and Br?nsted acids traditionally applied. Microporous zeolites are known to catalyze the reaction of simple substrates such as phenyl acetate, but their application to substituted derivatives has received limited attention. To refine structure-activity relationships, here we examine the impact of various parameters including the solvent polarity, water content, acidic properties, and framework type on the reaction scheme in the Fries rearrangement of p-tolyl acetate over common solid acids. The results confirm the importance of providing a high concentration of accessible Br?nsted acid sites, with beta zeolites exhibiting the best performance. Extension of the substrate scope by substituting methyl groups in multiple positions identifies a framework-dependent effect on the rearrangement chemistry and highlights the potential for the transformation of dimethylphenyl acetates. Kinetic studies show that the major competitive path of cleavage of the ester C-O bond usually occurs in parallel to the Fries rearrangement. The possibility of sequentially acylating the resulting phenol depends on the substrate and reaction conditions.
- Bonrath, Werner,Létinois, Ulla,Lin, Ronghe,Medlock, Jonathan,Mitchell, Sharon,Netscher, Thomas,Pérez-Ramírez, Javier,Stemmler, René T.
-
p. 4282 - 4292
(2020/07/30)
-
- 3-Ylidenephthalides as a new class of transient receptor potential channel TRPA1 and TRPM8 modulators
-
Following the recent identification of the naturally occurring 3-ylidene-4,5-dihydrophthalide ligustilide and its oxidation product dehydroligustilide as novel TRPA1 modulators, a series of seventeen 3-ylidenephthalides was synthesized and tested on TRPA1 and TRPM8 channels. Most of these compounds acted as strong modulators of the two channel types with EC50 and/or IC50 values distinctly lower than those of the reference compounds.
- Ortar, Giorgio,Schiano Moriello, Aniello,Morera, Enrico,Nalli, Marianna,Di Marzo, Vincenzo,De Petrocellis, Luciano
-
p. 5614 - 5618
(2013/10/01)
-
- Synthesis of ortho-acylphenols through the palladium-catalyzed ketone-directed hydroxylation of arenes
-
ortho-Acylphenols are an important structural motif found in a diversity of bioactive molecules ranging from natural products to drugs (Figure 1). Moreover, they also serve as versatile building blocks for the synthesis of various pharmaceuticals, such as warfarin, as well as agrichemicals, flavors, and fragrances. Classic approaches to the synthesis of o-acylphenols generally involve a two-step process: acylation of phenols followed by Fries rearrangement of the resulting phenyl esters (Scheme 1a). On the other hand, direct C-acylation of phenols has also been known under more forcing conditions. Although effective, these approaches are often complicated by the formation of undesired p-substituted products when bulky acyl groups need to be introduced, as well as the limited variety of ketones that can be generated.
- Mo, Fanyang,Trzepkowski, Louis J.,Dong, Guangbin
-
supporting information
p. 13075 - 13079
(2013/02/25)
-
- Regioselective ortho-acylation of phenol and naphthol derivatives catalyzed by FeCl3 under microwave conditions
-
Phenol and naphthol derivatives were subjected to regioselective solvent-free ortho-acylation with organic acids in the presence of FeCl 3 under microwave irradiation. The reactions were complete in a short time, and the products were obtained in high yields.
- Naeimi,Moradi
-
body text
p. 1757 - 1759
(2009/09/29)
-
- Microwave assisted direct ortho-acylation of phenol and naphthol derivatives by BF3·(C2H5)2O
-
The solventless acylation of phenol and naphthol derivatives with various organic acids and BF3·(C2H5) 2O, under microwave conditions, was studied. High yields of the o-acylated products were achieved in a very short time.
- Naeimi, Hossein,Moradi, Leila
-
p. 284 - 287
(2008/02/04)
-
- Biomolecular labeling
-
A method for using an organic compound to label polynucleotides is described. The method utilizes an organic compound including an oligonucleotide, and electrophilic active site, an active complex, and a phosphate binding site. The oligonucleotide has a sequence that is complimentary to a specific region of a polynucleotide. This facilitates labeling of DNA or RNA at a specific site in its sequence. The active site consists of a stable precursor, and only becomes reactive upon activation. Leaving and protecting functional groups may be attached to the active site in order to facilitate the formation of a stable precursor and subsequent activation. The active complex may be a drug, polypeptide or a reporter molecule such as an isotope or fluorescing compound. The phosphate binding sites may be any functional group capable of forming ionic bonds with phosphate oxygens. Nucleotide labeling using this compound does not interfere with a polynucleotide sequence. The described method for utilizing this compound may be performed in situ. Latent reactivity is utilized to make the reaction chemically specific, alkylating only phosphodiester groups on the polynucleotide. A lactonization reaction traps the trialkylphosphate in a stable form.
- -
-
Page/Page column 89
(2010/01/31)
-
- Fungicidal arylpyrazoles
-
The present invention relates to new derivatives of the family of 3-arylpyrazoles of formula (I), their methods of preparation, the compositions containing them and their utilization for the protection of plants against fungal diseases. STR1
- -
-
-
- Zirconium tetrachloride as a mediator for ambient temperature ortho-Fries rearrangements
-
Zirconium tetrachloride has been found to be an excellent mediator of the Fries reaction. Rearrangements occur at ambient temperature and are highly selective; giving the acetophenone derived from acetyl migration to the sterically least encumbered adjacent carbon.
- Harrowven, David C.,Dainty, Richard F.
-
p. 7659 - 7660
(2007/10/03)
-
- The Photo-Fries Rearrangement in the Presence of Potassium Carbonate: A Convenient Synthesis of ortho-Hydroxyacetophenones
-
Phenyl acetates 1 are converted into o-hydroxyacetophenones 2 in 78-90percent yields by photolysis in hexane solution in the presence of potassium carbonate.
- Garcia, Hermenegildo,Primo, Jaime,Miranda, Miguel Angel
-
p. 901 - 902
(2007/10/02)
-