Reaction of Grignard reagents with β-dicarbonyl compounds. II. Synthesis of β-hydroxyketones from 2,4-pentanedione

1967 ◽  
Vol 45 (15) ◽  
pp. 1761-1765 ◽  
Author(s):  
P. Canonne ◽  
L. C. Leitch
Keyword(s):  
Grignard Reagents ◽  
Magnesium Bromide ◽  
Dicarbonyl Compounds ◽  
Girard’S Reagent ◽  
Derivatives Of ◽  
By Products

Several new β-hydroxyketones having the formula CH3R′C(OH)CH2COCH3 have been prepared by the action of Grignard reagents on 2,4-pentanedione. With benzyl-, o-xylyl-, p-xylyl-, 3,4-dimethylbenzyl-, 2,5-dimethylbenzyl-, 3,5-dimethylbenzyl-, and α-naphthylmethyl-magnesium chlorides, 60 to 75% yields of the β-hydroxyketones were obtained. Phenyl-, p-tolyl-, and p-trifluoromethylphenyl-magnesium bromide and 2,4-dimethylbenzylmagnesium chloride gave lower yields, whereas with α-naphthylmagnesium bromide no β-hydroxyketone was formed. The β-hydroxyketones were separated from non-ketonic by-products by means of Girard's reagent T or P. Solid derivatives of the β-hydroxyketones could not be prepared.

scholarly journals Synthesis of new derivatives of copper complexes of Josiphos family ligands for applications in asymmetric catalysis

2014 ◽  
Vol 4 (7) ◽  
pp. 1997-2005 ◽  
Author(s):  
R. Oost ◽  
J. Rong ◽  
A. J. Minnaard ◽  
S. R. Harutyunyan
Keyword(s):  
Asymmetric Catalysis ◽  
Copper Complexes ◽  
Grignard Reagents ◽  
Aromatic Ketones ◽  
Asymmetric Catalytic ◽  
Catalytic Addition ◽  
Derivatives Of

New derivatives of copper complexes of Josiphos family ligands have been prepared and studied in asymmetric catalytic addition of Grignard reagents to enones, enoates and aromatic ketones.

CHARACTERIZATION OF ACTIVE COMPOUNDS FROM CITRUS PEELS BY-PRODUCTS USING CHROMATOGRAPHIC AND OPTIC METHODS

2017 ◽  
Vol 31 (2) ◽  
pp. 41-47
Author(s):  
Cristina Mihali ◽  
◽  
Thomas Dippong ◽  
Anca Dumuţa ◽  
◽  
...  
Keyword(s):  
Visible Region ◽  
Citrus Fruit ◽  
Volatile Oils ◽  
Complex Composition ◽  
Citrus Peels ◽  
Layer Chromatography ◽  
Derivatives Of ◽  
By Products ◽  
Extracting Agents

Citrus fruits such as orange, grapefruit, lemon and other citrus fruit are widely cultivated and processed generating large amounts of by-products. Citrus peels contain various compounds of economic importance such as volatile oils, flavonoids, polyphenols, carotenoids etc. It is essential to valorize the wastes of citrus processing. In this purpose, peels of orange, grapefruit and lemon, fresh and dried were subjected to extraction using trichloromethane and dichloromethane as extracting agents and analyzed by thin layer chromatography on silica gel plates. Visualization at 366 nm and 254 nm showed a complex composition of extracts that contain terpenes, oxygen heterocyclic substances derivatives of coumarin and carotenoids. The UV-VIS spectra of the extracts were recorded showing absorption in UV and Visible region.

scholarly journals A derivatization-directed three-component synthesis of fluorescent spiro [dihydropyridine-4,3ʹ-indoline]s

2020 ◽  
Vol 44 (9-10) ◽  
pp. 527-531
Author(s):  
Faranak Najafizadeh ◽  
Kurosh Rad-Moghadam ◽  
Soraya Yaghoubi Kalurazi
Keyword(s):  
Ring Opening ◽  
Derivatives Of ◽  
Isatin Derivatives ◽  
Coumarin Ring ◽  
By Products

The synthesis of spiro[chromeno[4,3- b]pyrazolo[4,3- e]pyridine-7,3ʹ-indoline]s is achieved via three-component reactions of 5-amino-3-methylpyrazole, 4-aminocoumarin, and isatin derivatives. This protocol provides expedient synthesis of 10-unsubstituted derivatives of the parent heterocyclic spiro framework and does not lead to coumarin ring opening. The synthesis is highly convergent as no by-products are present in the reaction mixtures. The spiro products show violet fluorescence emissions depending on the nature of their substituents.

Silyl Derivatives of the Mixed Sandwiches Cyclopentadienyl Manganese Benzene and Cyclopentadienyl Manganese Biphenyl, CpMn(C6H6) and CpMn(C6H5-Ph)

1997 ◽  
Vol 52 (9) ◽  
pp. 1037-1042 ◽  
Author(s):  
Max Herberhold ◽  
Thomas Hofmann ◽  
Stefanie Weinberger ◽  
Bernd Wrackmeyer
Keyword(s):  
Nmr Spectroscopy ◽  
Membered Ring ◽  
Grignard Reagents ◽  
Sandwich Complexes ◽  
Subsequent Reaction ◽  
Silyl Derivatives ◽  
Magnesium Halide ◽  
Derivatives Of

Mixed manganese sandwich complexes containing a silyl-substituted cyclopentadienyl ring, e. g. (η5 - C5H4 - R)Mn(η6- C6H6) (3a - c) and (η5- C5H4 - R)Mn(η6- C6H5 - Ph) (4a - c); (R = SiMe3 (a), Si2Me5 (b) and SiMe2tBu (c)), were obtained in low yield via intermediates {(η5 - C5H4 - R)MnCl} and their reaction with phenyl Grignard reagents. Use of the 4-trimethylsilyl-phenyl magnesium halide in the reaction with the intermediate {CpMnCl} led to complexes with silylsubstituted arene rings, CpMn(η6 - C6H5 - R′) (5a) and CpMn(η6 -R′ - C6H5 - C6H5 - R′) (6a); (R′ = SiMe3 (a)). Dilithiation of CpMn6H6) (1) and subsequent reaction with a chlorosilane gave (η5-C5H4 - R)Mn(η6 - C6H5 - R′) (7a,b); (R = R′ = SiMe3 (a), Si2Me5 (b)). A cyclophane 8 in which five- and six-membered ring are linked through a -Me2Si-SiMe2- bridge was obtained using 1,2-dichloro-tetramethyldisilane. The mixed manganese sandw ich complexes were thoroughly characterized by 1H , 13C, 29Si and 55Mn NMR spectroscopy. The 55Mn spectra can be used to detect low-yield side-products.

Photoreaktionen von Dekacarbonyldirhenium mit Allen und unverzweigten Allenderivaten / Photoreactions of Decacarbonyldirhenium with Allene and Unbranched Derivatives of Allene

1995 ◽  
Vol 50 (4) ◽  
pp. 649-660 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Wolfgang Michels ◽  
Gerhard Heeb
Keyword(s):  
Nmr Spectra ◽  
Crystal And Molecular Structure ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Oxidative Rearrangement ◽  
Dirhenium Complexes ◽  
Derivatives Of ◽  
By Products

Decacarbonyldirhenium (1) reacts upon UV irradiation with allene (2), 1,2-butadiene (3) and 2,3-pentadiene (4) preferentially by CO substitution and oxidative rearrangement to the corresponding enneacarbonyl-μ-η1:3-endiyl-dirhenium complexes 5, 9, and 15 and to the octacarbonyl-μ-η2:2-allene-dirhenium complexes 6, the stereoisomers 10, 11, and 16. At elevated temperature 5, 9, and 15 loose CO and yield by a reductive rearrangement also the complexes 6, 10, 11, and 16. In addition to these main products, depending upon the allene derivative used, various by-products are obtained.By-products of the reaction o f 1 with 2 are octacarbonyl-μ-η3:3-(2,3-dimethylene-buta-1,4- diyl)dirhenium (7) and μ-η2:2-allene-hexacarbonyl-μ-η1:3-1-propene-1,3-diyl-dirheniurn (8). The photo reaction of 1 with 3 yields, in addition to 9-11, tetracarbonyl-η3-(E-5-ethylidene- 4-methyl-2-cyclopenten-1-yl)rhenium (12) and tetracarbonyl-η3-(Z-5-ethyliden-4- methyl-2-cyclopenten-1-yl)rhenium (13) as a mixture of isomers. 1 and 4 form the by-products tetracarbonyl-η3-(EZ-3-penten-2-yl)rhenium (17), tetracarbonyl-η3-(EE-3-penten-2-yl)rhenium (18) and heptacarbonyl-μ-η1:2:1:2-(4,5-dimethyl-2,6-octadiene-3,6-diyl)dirhenium (19) with an unusually bridging and chelating ligand. The constitutions of the reaction products have been concluded from the IR and 1H NMR spectra. For 19 the crystal and molecular structure has been determined by X-ray diffraction analysis.

scholarly journals A facile synthesis of phenazine and quinoxaline (new 1,4-benzo diazine) derivatives using magnesium sulfate heptahydrate as a catalyst

2011 ◽  
Vol 76 (9) ◽  
pp. 1191-1198 ◽  
Author(s):  
Bahador Karami ◽  
Saeed Khodabakhshi
Keyword(s):  
Catalytic Activity ◽  
Magnesium Sulfate ◽  
Room Temperature ◽  
Facile Synthesis ◽  
Dicarbonyl Compounds ◽  
Sulfate Heptahydrate ◽  
Quinoxaline Derivatives ◽  
Work Up ◽  
Derivatives Of

Convenient and simple procedures for the synthesis of phenazine and quinoxaline derivatives were developed via a reaction of ophenylenediamines and 1,2-dicarbonyl compounds. In addition, the synthesis of two new derivatives of 1,4-benzo diazine derivatives and the catalytic activity of magnesium sulfate heptahydrate (MgSO4?7H2O) in the room temperature condensation of o-phenylenediamines and 1,2- dicarbonyl compounds in ethanol as solvent are reported. This method has many appealing attributes, such as excellent yields, short reactions times, and simple work-up procedures.

Some piperazino analogues of methadone and related ketones: a novel conversion of an N-carbethoxy to a triethylmethyl group

1969 ◽  
Vol 47 (13) ◽  
pp. 2413-2419
Author(s):  
J. R. Dimmock ◽  
N. J. Harper ◽  
R. Islam ◽  
A. F. Casy
Keyword(s):  
Cyano Group ◽  
Magnesium Bromide ◽  
Dimethylamino Group ◽  
Ethyl Magnesium Bromide ◽  
Derivatives Of ◽  
Related Compounds

A number of derivatives of methadone and related compounds have been prepared, where the dimethylamino group has been replaced by a 4-substituted piperazino function. The preparation of these compounds involved the reaction of N-ω-cyanoalkyl-N′-carbethoxy piperazines with ethyl magnesium bromide, and various products were obtained. These included replacement of the N′-carbethoxy group by a triethylmethyl function and cleavage of the carbethoxy group. In some cases the ω-cyano group reacted to give the corresponding ketone. Reactions of 1-benzyl-4-carbethoxy piperazine with ethyl magnesium bromide and phenyl magnesium bromide gave no evidence for the formation of the triethylmethyl group. However, cleavage of the carbethoxy group occurred and there was evidence for the formation of the corresponding amide.

Sign in / Sign up

Export Citation Format

Share Document