THE SYNTHESIS OF α-MONOFLUOROALKANOIC ACIDS

1965 ◽  
Vol 43 (6) ◽  
pp. 1700-1713 ◽  
Author(s):  
F. L. M. Pattison ◽  
R. L. Buchanan ◽  
F. H. Dean
Keyword(s):  
Functional Groups ◽  
Hydrogen Fluoride ◽  
Biologically Active ◽  
Fluorine Compounds ◽  
Perchloryl Fluoride

α-Monofluoroalkanoic acids are important intermediates in the synthesis of biologically active fluorine compounds. General methods of preparation have been examined, based on the three following reagents: (a) hydrogen fluoride + N-bromoacetamide; (b) diethyl monofluoromalonate; and (c) perchloryl fluoride. The first of these is the recommended procedure for simple unsubstituted α-fluoro acids; however, the fluoromalonate route is less vigorous, and is therefore the method of choice for those α-fluoro acids that contain labile functional groups.

scholarly journals Study of the biologically active acyclic ureas by nuclear magnetic resonance

2020 ◽  
Vol 100 (4) ◽  
pp. 60-74
Author(s):  
А.А. Bakibaev ◽  
◽  
М.Zh. Sadvakassova ◽  
V.S. Malkov ◽  
R.Sh. Еrkasov ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Functional Groups ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Biologically Active ◽  
Resonance Spectroscopy ◽  
13C Nmr Spectra ◽  
Nuclear Magnetic

A wide variety of acyclic ureas comprising alkyl, arylalkyl, acyl, and aryl functional groups are investigated by nuclear magnetic resonance spectroscopy. In general, spectral characteristics of more than 130 substances based on acyclic ureas dissolved in deuterated dimethyl sulfoxide at room temperature are studied. The re-sults obtained based on the studies of 1H and 13C NMR spectra of urea and its N-alkyl-, N-arylalkyl-, N-aryl- and 1,3-diaryl derivatives are presented, and the effect of these functional groups on the chemical shifts in carbonyl and amide moieties in acyclic urea derivatives is discussed. An introduction of any type of substitu-ent (electron-withdrawing or electron-donating) into urea molecule is stated to result in a strong upfield shift in 13C NMR spectra relatively to unsubstituted urea. A strong sensitivity of NH protons to the presence of acyl and aryl groups in nuclear magnetic resonance spectra is pointed out. In some cases, qualitative depend-encies between the chemical shifts in the NMR spectra and the structure of the studied acyclic ureas are re-vealed. A summary of the results on chemical shifts in the NMR spectra of the investigated substances allows determining the ranges of chemical shift variations of the key protons and carbon atoms in acyclic ureas. The literature describing the synthesis procedures are provided. The results obtained significantly expand the methods of reliable identification of biologically active acyclic ureas and their metabolites that makes it promising to use NMR spectroscopy both in biochemistry and in clinical practice.

scholarly journals The impact of functional groups of the surface of carbon materials on the efficiency of purification of extraction phosphoric acid from fluorine compounds

2019 ◽  
Vol 2 ◽  
pp. 11-18
Author(s):  
Smirnov N.N. ◽  
Konoval A.V. ◽  
Smirnova D.N. ◽  
Kochetkov S.P.
Keyword(s):  
Phosphoric Acid ◽  
Functional Groups ◽  
Carbon Materials ◽  
Raw Materials ◽  
Carbon Adsorbents ◽  
Joint Stock Company ◽  
Stock Company ◽  
Fluorine Compounds ◽  
The Impact ◽  
Extraction Phosphoric Acid

The environmental problems of the production of extraction phosphoric acid and the effect of fluorine on the human body are discussed in the article. The creation of the industry of phosphoric fertilizers on the basis of processing of fluorine-containing phosphate raw materials and fluorine-containing compounds, the development of their application require the study of environmental consequences arising from this, because fluorine is characterized by high mobility in the biological cycle of metabolism. For the purification of phosphoric acid from fluorine was used carbon adsorbents such as active charcoal brand BAU, natural graphite deposits Kyshtymsky, P514 soot, charcoal. Experiments on the purification was carried out on non-evaporated half-hydrated extraction phosphoric acid which was produced by joint stock company «Apatit» in Cherepovets city in Russia. The following analyses were carried out: IR-Fourier spectrometry, research of acid–base properties of carbon materials by potentiometric titration, potentiometric method of fluorine determination in extraction phosphoric acid. It is mentioned that the carbon black P514 is the most efficient adsorbent for purification of extraction phosphoric acid. The total number of functional groups on its surface is 0.62 mmol/g, the degree of purification from fluorine compounds is 94.8%.

Synthesis of a biologically active isomer of frontalin and some new products from acylative decarboxylation of 3-methyltricarballylic acid

1990 ◽  
Vol 68 (5) ◽  
pp. 782-786 ◽  
Author(s):  
George M. Strunz ◽  
Chao-Mei Yu ◽  
Li Ya ◽  
Peter S. White ◽  
E. A. Dixon
Keyword(s):  
Acetic Anhydride ◽  
Functional Groups ◽  
Bark Beetles ◽  
New Products ◽  
Major Product ◽  
Biologically Active ◽  
Catalysed Reaction ◽  
Active Isomer ◽  
Pheromone Analogue ◽  
Simple Manipulation

2-Acetonyl-2-methylsuccinic anhydride, 3, the major product from base-catalysed reaction of 3-methyltricarballylic acid with acetic anhydride, was converted by simple manipulation of functional groups into 1,5-dimethyl-2,7-dioxabicyclo[3.2.1]octane. This bicyclic ketal (6) is isomeric with frontalin, 7, an aggregation pheromone for Dendroctonus bark beetles. It elicited electroantennogram responses in D. ponderosae and D. rufipennis. Besides 3 and the known compounds, 4 and 5, two new minor products, 8 and 9, were identified from base-catalysed acylative decarboxylation of 3-methyltricarballylic acid. Keywords: pheromone analogue, Dendroctonus, bark beetles.

Biologically active acyclonucleoside analogues. II. The synthesis of 9-[[2-hydroxy-1-(hydroxymethyl)ethoxy]methyl]guanine (BIOLF-62)

1982 ◽  
Vol 60 (24) ◽  
pp. 3005-3010 ◽  
Author(s):  
Kelvin K. Ogilvie ◽  
Ukken O. Cheriyan ◽  
Bruno K. Radatus ◽  
Kendall O. Smith ◽  
Karen S. Galloway ◽  
...  
Keyword(s):  
Chemical Synthesis ◽  
Functional Groups ◽  
Biologically Active ◽  
Nucleoside Analogues ◽  
Naturally Occurring

The chemical synthesis of 9-[[2-hydroxy-1-(hydroxymethyl)ethoxy]methyl]guanine is described. This compound, known as BIOLF-62, is active against herpesviruses. This compound is a member of a novel class of nucleoside analogues which lack a rigid carbohydrate ring, but which possess all of the functional groups of naturally occurring deoxynucleosides.

scholarly journals Study of the content of fluorides in atmospheric air in Bokhtar region and Tursunzade city of Tajikistan

2021 ◽  
Vol 2 (1) ◽  
pp. 11-18
Author(s):  
Khuseyn Egamnazarov ◽  
Babaev Ikram Islamovich ◽  
Aliev Samardin Partoevich ◽  
Abdullozoda Said Murtazo
Keyword(s):  
Hydrogen Fluoride ◽  
Hydrofluoric Acid ◽  
Maximum Amount ◽  
Public Healthcare ◽  
Control Zone ◽  
Atmospheric Air ◽  
The Public ◽  
Fluorine Compounds ◽  
And Control ◽  
The City

Background: The emission and presence of air pollutants such as fluorides has over burdenized the public healthcare issues. The current study aimed to determine the content of fluorides in atmospheric air in Bokhtar region and Tursunzade city of Tajikistan. Methods: Based on the direction of wind, two zones were selected in the current study: experimental and control. In the first (experimental) zone, those areas were selected where the western, northern and northeastern directions of wind was significant. Dzhura Rakhmonov was assigned to the control zone with the shortest time for the eastward winds. In general, 72 samples of atmospheric air were taken in 12 settlements of the city of Tursunzade and 90 samples of atmospheric air in the Bokhtar region of the Khatlon province. To determine fluorine in air, a potentiometric method with an ion-selective electrode was used, which makes it possible to measure the potential concentrations of fluorides in atmospheric air. Results: Compounds of gaseous (hydrogen fluoride) and solid fluorine (salts of hydrofluoric acid), which are the main emission from various sources, were found in the atmospheric air of the populated areas of the city of Tursunzade, where the aluminum plant industry is located. The maximum amount of hydrogen fluoride in the experimental zone (Jamoat and Navobod) with a western wind direction was found in the autumn, which exceeded the MPC. However, the amount of solid fluorides in the western direction of the wind ranged from 0.01 to 1.0 mg / m3, which did not exceed the MPC value and was not significant. In control zone (Dzhura Rakhmonov) the said pollutants hydrogen fluoride and solid fluorine were not significant in autumn within accordance to MPC limit. The results of the study of atmospheric air in 15 administrative cities and districts of the Bokhtar region showed a complete absence of solid fluorides in all samples of atmospheric air. Conclusion: Compounds of gaseous fluorine and salts of hydrofluoric acid were found in the atmospheric air of populated areas of the city of Tursunzade, and no significant amounts in the Bokhtar region according to MPC and control. The maximum amount of fluorine compounds was found in the experimental zone (Jamoat Navobod) of the city of Tursunzade.

Hypervalent Iodine-mediated/Catalyzed Oxidative Cycloisomerization/Annulation of Alkynes for Metal-free Synthesis of Oxazoles

2020 ◽  
Vol 24 (18) ◽  
pp. 2048-2069
Author(s):  
Akio Saito
Keyword(s):  
Functional Groups ◽  
Single Step ◽  
Biologically Active ◽  
Hypervalent Iodine ◽  
Sustainable Chemistry ◽  
Metal Free ◽  
Triple Bonds ◽  
Iodine Species ◽  
Low Toxicity ◽  
Synthetic Intermediates

Since oxazoles have found widespread applications not only as synthetic intermediates but also as biologically active compounds, much effort has been focused on developing novel and efficient methods for the synthesis of this heterocycle. From the viewpoint of green and sustainable chemistry, hypervalent iodine and other halogen reagents have gained increasing popularity in metal-free oxidative transformation due to their low toxicity, transition-metal-like reactivity, high stability, easy handling and other benefits. In this account, our two approaches to the metal-free synthesis of oxazoles by means of a peculiar activation of alkynes by iodine species are described with the related contexts. One is iodine(III)-mediated/catalyzed oxidative cycloisomerization reactions of N-propargyl amides for the preparation of oxazoles bearing various functional groups at their side chains. In these reactions, iodine(III) species works as a donor of various heteroatomic functional groups as well as an activator of carbon-carbon triple bonds in a single step. Furthermore, this methodology can be extended to iodine(III)-mediated/catalyzed oxidative annulation of alkynes and nitriles as another approach, in which heteroatoms on iodine(III) species are incorporated in the azole rings.

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