Difluoroaniline

DIFLUOROBENZENES Interest in the commercialization of difluoroaromatics in crop protection chemicals and dmgs (Table 5) continues to be strong. Numerous liquid crystals containing the 1,2-difluorobenzene moiety have been synthesized. Table 6 lists physical properties of commercially significant intermediates such as o-, m-, and -difluorobenzene, 2,4-difluoroaniline and 2,6-difluorobenzonitrile. The LD q values for the three isomeric difluorobenzenes are identical 55 g/m for 2 h (inhalation, mouse) (127). 

Trifluorobenzene. This compound is formed ia low yield (13—24%) from l,2,3-trichloroben2ene or 2,3-difluorochloroben2ene and KF/CsF ia dimethyl sulfone (204). Likewise, low yields are reali2ed when the Bal2-Schiemann reaction is appHed to 2,3-difluoroaniline or... 

Reaction of 2-chloro-6H-pyrido[l,2-fc]pyridazin-6-ones 14 with phenols, thiophenols, 2,4-difluorobenzyl zinc bromide, biphen-2-ylboronic acid, 2,4-difluoroaniline, and NH4OH/NH4CI afforded different 2-substituted 6H-pyrido[l,2-fc]pyridazin-6-ones 15-20 (Scheme 1) (07USA2007/... 

The mixture was stirred for 1 hour at room temperature. Methanol was evaporated and the residue was extracted with chloroform. After the extract was washed with water and dried, the solvent was evaporated to provide 0.44 g of 2-(2-bromoethoxy)-3,4-difluoroaniline. 

Although o-bromo, o-chloro, ° and o-iodo anilines give 7-haloisatins, o-fluoroaniline has been reported not to give an isatin. 2,4-Difluoroaniline also fails to give an isatin although cyclization... 

Halogen exchange with a fluoride anion is one of the two main techniques to introduce a fluorine atom on an aromatic nucleus, which is a useful complement of diazotization of anilines in hydrogen fluoride or thermal decomposition of arenediazonium fluoroborates (Schiemann reaction). It is used on an industrial scale to produce, for example, 2,6-difluorobenzonitrile (the precursor of the insecticide Diflubenzuron) or 2,4-difluoroaniline (the precursor of Diflufenican or other herbicides). 

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