Activated halogen groups

This topic has been reviewed [2, pp 94, 100-111, 130-134] All of the standard approaches to the synthesis of a compound like methyl 2-fluorostearate from methyl 2-bromostearate result mall yield of the 2-fluoro ester and the unsaturated esters. Although silver fluoride is not a new reagent, its use moist in wet acetonitrile to convert methyl 2-bromostearate to its fluoro ester is a departure from the traditional set of anhydrous conditions (Procedure 6, p 194) [71] In contrast, silver tetrafluoroborate converts a-chloroketones to their respective fluoroketones under anhydrous conditions. The displacement of less activated halogen groups by silver tetrafluoroborate to form their respective fluorides is novel Although silver tetrafluoroborate could not be used to convert an aliphatic terminal dichloromethyl or trichloromethyl group to its corresponding fluoro derivative, it is an effective fluorine source in other situations [72] (Table 8)... 

Active halogen groups were bonded to a glass surface by nonhydrolyzable links using the reactions set out in Scheme (40) ... 

Dissolve SIAB (Thermo Fisher) in DMSO at a concentration of 1.4mg/ml. Prepare fresh and protect from light to avoid breakdown of the active halogen group. 

The displacement of less activated halogen groups by silver(I) tetrafluoroborate to the corresponding fluorides is not so widespread. Although silver(I) tetrafluoroborate cannot be used to transform an aliphatic terminal dichloromethyl or trichloromethyl group to the corresponding fluoro compound, it has been known to work in many other cases (Table 13).70... 

CS and CN are SN2-alkylating agents with activated halogen groups that react readily at nucleophilic sites. The prime targets include... 

SCN, Isothiocyanate OSu, succinimidyl active ester lAA, iodoacetamide MAL, maleimide SO Cl, sulfonyl chloride Cl, active halogen group —SS—, disulfide exchange reaction involving SPDP [A/-succinimidyl 3-(2-pyridyldithio)propionate)] NBD, 7-nitrobenz-2-oxa-1,3-diazole DAPI, 4, 6-diamidino-2-phenylindole DCDHB, dicyanodihydroxybenzene PBS, phosphate-buffered saline. 

Substances with an activated halogen group in the apposition or/and in the vinyl position to an electronegative group E (IIL13)... 

The following microbicides with activated halogen groups have already been described within other substance classes ... 

Appropriate active ingredients for non-persistent slimicides one finds above all among the compounds with activated halogen groups (III.7 and III.15). Other active ingredients belong to the carbamates (III.9 and III.3.4.10.1) and the heterocyclic N,S compounds (III. 13). It is also proposed to use glutaraldehyde (III.2.3) or 3,5-dimethyl-tetrahydro-2-thiono-thiadiazine (III.3.3.16). 

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