Fluorine reagent

The selective fluorine reagent-FTB is mainly used as a fluorinating agent, and can perform a monofluorination reaction on an electron-rich double bond, an enol silyl ether, an enol lithium salt, etc., for preparing a fluorine-containing steroid drug. [Application Fields] 1. Direct fluorination Direct fluorination method refers to the direct introduction of fluorine on non-fluorine substrates by electrophilic or nucleophilic fluorination reagents. Various direct or indirect fluorinating reagents react with certain groups of the substrate to form the desired fluorochemical. Commonly used fluorinating agents include: (A) nucleophilic fluorinating agents such as HF, n-Bu4NF, SF4, DAST, etc., and metal fluorides NaF, KF, AgF, HgF2, SbF3 and the like. (B) Electrophilic or electrophilic free radical fluorinating reagents, including F2, XeF2, chlorofluoro acid (FClO3), CF3OF, and "N?F" reagents (including Selectfluor?, NFSI, etc.), such as in 2005 The MacMillan group reported an asymmetric electrophilic fluorination reaction (Scheme 2) catalyzed by small organic molecules using NFSI as a fluorinating reagent. However, in the direct fluorination method, these fluorinating reagents are either too toxic or expensive, and some reaction conditions are severe, difficult to control, and poor in selectivity, so that introduction of fluorine atoms in specific molecules or at specific positions of molecules is affected. The limit. 2. Fluorine reagent colorimetric method Fluoride in food is reacted with acid in a diffusion box to generate hydrogen fluoride gas, which is absorbed by sodium hydroxide through diffusion. Fluoride ion and hydrazine, fluorine reagent (alkine aminocarboxylate complexing agent) form a blue ternary complex at a suitable pH, the color deepens with the increase of fluoride ion concentration, with or without an amine-based organic solvent extraction, and The standard series is more quantitative. It is extracted by monoamine method with amine-containing organic reagent, and its sensitivity is higher. The minimum detection amount is 0.1mg/kg. It is easy to operate without the extraction of amine-containing organic reagents. The minimum detection amount is 0.2mg/ Kg. 3. Fluorine reagent spectrophotometry A method for determining the fluoride content in surface water, groundwater and industrial wastewater. The principle is: fluoride ion reacts with fluorine reagent and lanthanum nitrate in a buffer medium of pH 4.1 to form a blue ternary complex. The intensity of the color is proportional to the concentration of fluoride ion, and the fluoride is quantitatively determined at a wavelength of 620 nm. Content (in terms of F-). In the 25mg color developing solution containing 5g of fluoride, when the following ions exceed the following content (in mg), there is interference with the measurement, which can be eliminated by pre-distillation: Cl-30; SO42-5.0; NO3-3.0; B4O72 -2.0; Mg2+2.0; NH4+1.0; Ca2+0.5. The minimum detectable concentration of this method is fluoride fluoride 0.05 mg / L (in terms of F -), and the upper limit concentration is 1.80 mg / L. This law has been designated as the national standard analysis method (GB7483-87). [Fluorine classification] (1) Deoxo fluorination Deoxo-Fluor? Reagent is a versatile, easy to use, safer nucleophilic fluorinating reagent. It rapidly "deoxyfluorinates" various alcohols, aldehydes and ketones under mild conditions to produce the corresponding fluorides with high efficiency and selectivity. Deoxo-Fluor reagents are less heat sensitive than traditional deoxyfluorination agents DAST and are therefore more suitable for large scale applications. (2) Electrophilic fluorination The Selectfluor® series of reagents are a series of NF-type electrophilic fluorides that can be used in pharmaceutical and agricultural applications. This range of reagents includes Selectfluor I and Selectfluor II reagents. Both reagents are versatile and safe to use reagents that fluorinate specific locations in complex molecules. Selectfluor reagents selectively, efficiently and rapidly fluorinate various organic molecules under mild conditions. In many cases, Selectfluor reagents can replace toxic or explosive fluorinating agents such as FClO3 or CF3OF. Selectfluor reagents are a convenient, simple alternative to your fluorination process. Various fluorination reagents have been tested and used in the pharmaceutical and agricultural industries, including NF-type electrophiles. However, many of these agents have serious limitations. Some reagents have proven to be expensive and difficult to prepare and therefore not economically viable. Other fluorinating agents attempted lack sufficient fluorination efficiency to make the synthesis of the chemical cost-effective, or the impurities produced in the process require additional processing steps to remove. Selectfluor reagents solve all of these problems. Selectfluor reagents are packaged in convenient quantities for easy evaluation and commercial production. Source of this information: Air Products is a world-leading industrial gas company.