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US 4,051,168 AGranted
Fluorination process
AssigneeE. I. Du Pont de Nemours and Company
InventorAndrew Edward Feiring
Life of this patent
Estimating the term…
Abstract
Aromatic compounds containing an .alpha.-fluoroalkyl or .alpha.,.alpha.-difluoroalkyl side chain are prepared by reacting selected aromatic compounds with a mixture of HF and a metal oxide which is PbO.sub.2 or NiO.sub.2 at -30.degree. to +80.degree. C. Exemplary is the conversion of 4-nitrotoluene to 4-(fluoromethyl)nitrobenzene and 4-(difluoromethyl)nitrobenzene.
Claims26
The fluorination process which consists essentially in reacting under substantially anhydrous conditions one mode of an aromatic compound of the formula ##STR32## wherein n is 1 to 3;
- a and b are each 0 or 1 with the proviso that n is at least 1 and the sum of n, a and b does not exceed 3;
- R is H, alkyl of 1-3 carbons or Z in which Z is F, Cl, Br or I;
- R.sup.21 and R.sup.2 are H or phenyl or together are 1,2-phthaloyl;
- X and Y are H, NO.sub.2, COOH, CHO, CONH.sub.2, COOR.sup.3, COR.sub.3, SO.sub.3 H, CF.sub.3, CN, SO.sub.2 OR.sup.3, SO.sub.2 NR.sub.2.sup.3, F, Cl, Br or I with the proviso that only one of X and Y can be H, F, Cl, Br or I;
- and
- R.sup.3 is alkyl of 1-4 carbons or phenyl;
- with at least three moles of HF and at least one mole of a metal oxide selected from the group consisting of lead dioxide and nickel dioxide at a temperature range of about -30.degree. to about +80.degree. C for about 10 minutes to about 22 hours with the proviso that when nickel dioxide is used it is the last reactant added, and recovering an aromatic compound having a mono- or di-fluorinated benzylic carbon compound.
4 more elements
Dependencies are inferred from the claim text.