I2/CuCl2-Copromoted Formal [4 + 1 + 1] Cyclization of Methyl Ketones, 2-Aminobenzonitriles, and Ammonium Acetate: Direct Access to 2-Acyl-4-aminoquinazolines

2021 ◽  
Author(s):  
Chun Huang ◽  
You Zhou ◽  
Xiao-Xiao Yu ◽  
Li-Sheng Wang ◽  
Yan-Dong Wu ◽  
...  
Keyword(s):  
Ammonium Acetate ◽  
Direct Access ◽  
Methyl Ketones

Reactions of Methyl Ketones and (Hetero)arylcarboxamides with N,N-Dimethylacetamide Dimethyl Acetal. A Simple Metal-Free Synthesis of 2,4,6-Trisubstituted Pyridines

2015 ◽  
Vol 68 (2) ◽  
pp. 184 ◽  
Author(s):  
Benjamin Prek ◽  
Uroš Grošelj ◽  
Marta Kasunič ◽  
Silvo Zupančič ◽  
Jurij Svete ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Single Crystal ◽  
Ammonium Acetate ◽  
Dimethyl Acetal ◽  
Methyl Ketones ◽  
Closed Vessel ◽  
Simple Metal ◽  
One Pot ◽  
X Ray ◽  
Metal Free

Two metal-free syntheses of 2,4,6-trisubstituted pyridines 10a–m and 16a–j are described. N,N,6-Trimethyl-4-(substituted)pyridin-2-amines 10 were prepared from aryl or heteroaryl methyl ketones which were transformed with N,N-dimethylacetamide dimethyl acetal (DMADMA) into enaminones 4a–m, followed by treatment with ammonium acetate to give (Z)-3-amino-1-(substituted)but-2-en-1-ones 5a–m. These were treated with DMADMA under microwave irradiation in a closed vessel at 130°C, to give via intermediates 7–9 the final products 10a–m. N2,N2,N4,N4-Tetramethyl-6-(substituted) pyridine-2,4-diamines 16a–j were prepared in a one-pot synthesis from the corresponding carboxamides 11a–j by treatment with an excess of DMADMA in a closed vessel under microwave irradiation to give via intermediates 12a–j to 15a–j the final products 16a–j. X-Ray single crystal diffractometry studies of the enaminones 5c, 5g, 5i, 5j, and 5m and 2,4,6-trisubstituted pyridines 16a, 16b, 16g, 16i, and 16j were consistent with the expected structures.

Palladium-Catalyzed Cross-Coupling of Styrenes with Aryl Methyl Ketones in Ionic Liquids: Direct Access to Cyclopropanes

2014 ◽  
Vol 126 (49) ◽  
pp. 13781-13785 ◽  
Author(s):  
Pietro Cotugno ◽  
Antonio Monopoli ◽  
Francesco Ciminale ◽  
Antonella Milella ◽  
Angelo Nacci
Keyword(s):  
Ionic Liquids ◽  
Cross Coupling ◽  
Direct Access ◽  
Methyl Ketones ◽  
Palladium Catalyzed ◽  
Aryl Methyl

Regiocontrolled synthesis of 2,4,6-triarylpyridines from methyl ketones, electron-deficient acetylenes and ammonium acetate

2021 ◽  
Vol 19 (12) ◽  
pp. 2703-2715 ◽  
Author(s):  
Dmitrii A. Shabalin ◽  
Marina Yu. Dvorko ◽  
Elena Yu. Schmidt ◽  
Boris A. Trofimov
Keyword(s):  
Ammonium Acetate ◽  
Methyl Ketones ◽  
Simple Method ◽  
Regiocontrolled Synthesis

A simple method to access unsymmetrical 2,4,6-triarylpyridines starting from available methyl ketones and electron-deficient acetylenes was developed.

Palladium-Catalyzed Cross-Coupling of Styrenes with Aryl Methyl Ketones in Ionic Liquids: Direct Access to Cyclopropanes

2014 ◽  
Vol 53 (49) ◽  
pp. 13563-13567 ◽  
Author(s):  
Pietro Cotugno ◽  
Antonio Monopoli ◽  
Francesco Ciminale ◽  
Antonella Milella ◽  
Angelo Nacci
Keyword(s):  
Ionic Liquids ◽  
Cross Coupling ◽  
Direct Access ◽  
Methyl Ketones ◽  
Palladium Catalyzed ◽  
Aryl Methyl

ChemInform Abstract: Palladium-Catalyzed Cross-Coupling of Styrenes with Aryl Methyl Ketones in Ionic Liquids: Direct Access to Cyclopropanes.

ChemInform ◽  
2015 ◽  
Vol 46 (17) ◽  
pp. no-no
Author(s):  
Pietro Cotugno ◽  
Antonio Monopoli ◽  
Francesco Ciminale ◽  
Antonella Milella ◽  
Angelo Nacci
Keyword(s):  
Ionic Liquids ◽  
Cross Coupling ◽  
Direct Access ◽  
Methyl Ketones ◽  
Palladium Catalyzed ◽  
Aryl Methyl

A simple synthesis of dimethyl 2-[(Z)-3-amino-1-oxo-1-(substituted)but-2-en-2-yl]fumarates: potential intermediates in the synthesis of polysubstituted five- and six-membered heterocycles

2016 ◽  
Vol 71 (6) ◽  
pp. 677-682 ◽  
Author(s):  
Rok Šinkovec ◽  
Uroš Grošelj ◽  
Benjamin Prek ◽  
Marta Počkaj ◽  
Sebastijan Ričko ◽  
...  
Keyword(s):  
Ammonium Acetate ◽  
Dimethyl Acetal ◽  
Simple Synthesis ◽  
Dimethyl Acetylenedicarboxylate ◽  
Methyl Ketones ◽  
Metal Free

AbstractIn this communication, a simple synthesis of dimethyl 2-[(Z)-3-amino-1-oxo-1-(substituted)but-2-en-2-yl]fumarates is described. Methyl ketones were transformed by treatment with N,N-dimethylacetamide dimethyl acetal (DMADMA) into 3-dimethylamino-1-(substituted)but-2-en-1-ones, followed by treatment with ammonium acetate into (Z)-3-amino-1-(substituted)but-2-en-1-ones and addition to dimethyl acetylenedicarboxylate. These novel polysubstituted butadienes are potential intermediates for the metal-free preparation of polysubstituted five- and six-membered heterocycles.

The structure of pre-mRNA and mRNA from erythroid cells

1978 ◽  
Vol 36 (2) ◽  
pp. 234-235
Author(s):  
A.-M. Ladhoff ◽  
B.J. Thiele ◽  
Ch. Coutelle ◽  
S. Rosenthal
Keyword(s):  
Bone Marrow ◽  
Structural Transformation ◽  
Electron Micrographs ◽  
Ammonium Acetate ◽  
Bone Marrow Cells ◽  
Erythroid Cells ◽  
Globin Mrna ◽  
Ordered Structures ◽  
Rabbit Bone ◽  
Rabbit Reticulocytes

The suggested precursor-product relationship between the nuclear pre-mRNA and the cytoplasmic mRNA has created increased interest also in the structure of these RNA species. Previously we have been published electron micrographs of individual pre-mRNA molecules from erythroid cells. An intersting observation was the appearance of a contour, probably corresponding to higher ordered structures, on one end of 10 % of the pre-mRNA molecules from erythroid rabbit bone marrow cells (Fig. 1A). A virtual similar contour was observed in molecules of 9S globin mRNA from rabbit reticulocytes (Fig. 1B). A structural transformation in a linear contour occurs if the RNA is heated for 10 min to 90°C in the presence of 80 % formamide. This structural transformation is reversible when the denatured RNA is precipitated and redissolved in 0.2 M ammonium acetate.

Electron Microscopy of the Nucleic Acid of Mouse Mammary Tumor Virus

1968 ◽  
Vol 26 ◽  
pp. 22-23
Author(s):  
N. H. Sarkar ◽  
Dan H. Moore
Keyword(s):  
Mammary Tumor ◽  
Mouse Mammary Tumor Virus ◽  
Ammonium Acetate ◽  
Dry Weight ◽  
Mouse Tumor ◽  
Mammary Tumor Virus ◽  
Rna Molecules ◽  
Mouse Mammary Tumor ◽  
Tumor Virus ◽  
The Subject

Mouse mammary tumor virus (MTV) is believed to contain about 0.8% single stranded ribonucleic acid (RNA). This value of RNA content was estimated on a dry weight basis. The subject of this report is an attempt to visualize the RNA molecules of MTV particles.MTV particles were isolated from RIII mouse (tumor incidence approximately 80%) milk according to the method described by Lyons and Moore. Purified virions from 5 ml of milk were finally suspended in 0.2 ml of PBS, pH 7.4 and was mixed with an equal volume of pronase (5 mg/ml). This mixture was incubated at 37°C for an hour. RNA was extracted three times using freshly prepared cold phenol. It was then treated three times with cold ethyl ether to remove any trace of phenol. The RNA thus extracted was divided into two parts. One part was diluted four fold with 8M urea to avoid aggregation of the molecules. The other part was left untreated. Both samples were then mixed with an equal volume of 1M ammonium acetate, adjusted to pH 8.0 with NH3 containing chymotrypsin at a concentration of 0.01%.

HVEM Cryomicroscopy of Frozen Hydrated PTK1 Cells

1990 ◽  
Vol 48 (1) ◽  
pp. 500-501
Author(s):  
E.T. O’Toole ◽  
G.P. Wray ◽  
J.R. Kremer ◽  
J.R. Mcintosh
Keyword(s):  
Liquid Nitrogen ◽  
Phase Contrast ◽  
Culture Medium ◽  
Low Dose ◽  
Ammonium Acetate ◽  
Freezing Point ◽  
Voltage Electron ◽  
Cold Stage ◽  
Humidity Chamber ◽  
Coated Carbon

Ultrarapid freezing and cryomicroscopy of frozen hydrated material makes it possible to visualize samples that have never been exposed to chemical fixatives, dehydration, or stains. In principle, freezing and cryoimaging methods avoid artifacts associated with chemical fixation and processing and allow one to visualize the specimen in a condition that is close to its native state. Here we describe a way to use a high voltage electron microscope (HVEM) for the cryoimaging of frozen hydrated PTK1 cells.PTK1 cells were cultured on formvar-coated, carbon stabilized gold grids. After three days in culture, the grids were removed from the culture medium and blotted in a humidity chamber at 35° C. In some instances, the grids were rinsed briefly in 0.16 M ammonium acetate buffer (pH 7.2) prior to blotting. After blotting, the grids were transferred to a plunging apparatus and plunged into liquid ethane held directly above its freezing point. The plunging apparatus consists of a vertical slide rail that guides the fall of a mounted pair of forceps that clamp the specimen. The forceps are surrounded by a plexiglass humidity chamber mounted over a dewar of liquid nitrogen containing an ethane chamber. After freezing, the samples were transferred to liquid nitrogen and viewed in a JEOL JEM 1000 equipped with a top entry cold stage designed and built by Mr. George Wray (Univ. Colorado). The samples were routinely exposed to electron doses of 1 e/Å2/sec, and viewed at a temperature of −150° C. A GATAN video system was used to enhance contrast and to estimate the correct amount of underfocus needed to obtain phase contrast at various magnifications. Low dose micrographs were taken using two second exposures of Kodak 4463 film. The state of the solid water in the specimen was determined by diffraction using a 30/μm field limiting aperture and a camera length of 1 meter.

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