If carboxylic acid posess N,N- dialkylamino group as substituent, then the direction of fluorination process doesn't change and both fluoroanhydrides of corresponding perfluorinated acids and heterocyclic compounds are formed. (table. 2) [27-31].

R1F	R2F	Yield,%
CF3	CF3	28,9
C2F5	C2F5	29,9
(CF2)4		43,3
CF2CF2OCF2CF2		55
(CF2)5		40,4
CF2CF2N(CF3)CF2CF2		22,7

These compounds are used as semi-products for creating of surfactants and monomers for fluorine containing polymers,  medications.
The yield of target products depends on carbon chain type. [32].

R1F	R2F	Yield, %
CF3	CF3	16,9
C2F5	C2F5	4,7
(CF2)4		21,2
CF2CF2OCF2CF2		13,5
(CF2)5		21
CF2CF2N(CF3)CF2CF2		14,7

It's interesting to note, that such perfluorinated compounds were used for synthesis of perfluoro-(N-vinyl amines) [33-35]. During polymerization the last mentioned ones produce films, which let pass selectively gases of certain type, this is used for gas separation, in particular for air oxygen enriching. 

At electrochemical fluorination of 2- pyrrolidine propionic acid  with further heating of fluorination product at 100-150 ^oC in the presence  of  basis the perfluorinated  N-vinyl substituted cyclic amines are formed [33-35]. These compounds can be used to obtain surfactants, dyes, medications. The detailed studying of this process showed [36-38] the influence of both process carrying out conditions and carbon chain structure on the formation of N-vinyl amines. 

Table 2. The results of N,N-dialkylamino substituted carboxylic acids electrochemical fluorination [27].

The yield of perfluorocarboxylic acids fluoroanhydrides depends on carbon chain length, connected with nitrogen atom. The following order regarding increasing of target product is determined [39].

The behavior of carboxylic acids esters, containing cyclic amine as substituent in -position, is analoguos at electrochemical fluorination.  The formation of entirely fluorinated compounds takes place, it goes with complete retaining of carbon skeleton and products of cyclic system reducing.[32, 40,41].

At the same time if this group is in  -position, then - disintegration of carbon chain occurs (more rarely the  opening of C-N bond) : the formation of perfluorinated trialkylamines occurs (current density 3.3 A/ dm², voltage 5.9-6.1 V, temperature 7-9 ^oC) [42-44].

The result of electrochemical fluorination of cis-2,6-dimethyl morpholine substituted carboxylic acids is the formation of fluoroanhydrides of corresponding acids along with other fluorination products [45-47].

The electrochemical fluorination of corresponding piperazine-N,N'-di--propionic acid results in  formation of the fluoroanhydride of perfluorinated  piperazine-N,N'-di--propionic acid [48,49]. These compounds are used as lubricating oils, water- and oilrepellent agents and medicines.

The electrochemical fluorination of alkoxycarboxylic acids results in formation of perfluorocarboxylic acid perfluoroalkyl esters (Electrochemical fluorination conditions: voltage 6.5 V, temperature 10 ^oC, current density 0.01-0.02 A/dm², Ni- anode, steel-3 as cathode) [50].

Higher perfluorocarboxylic acids [51] are obtained by telomeric alcohols H(CF₂CF₂)nCH₂OH , n = 2-5) electrochemical fluorination in anhydrous hydrogen fluoride. The obtained acids had found their application at emulsion polymerization of tetrafluoroethylene.

It should be noted, that direct fluorination of carboxylic acid derivatives by element fluorine have to be carried out in the solution of perfluorinated solvent fluorine-resistant. In the recent years the satisfactory results regarding both the fluorination process and target product yield are obtained. Thus the fluorination of succinic acid dimethyl ester using element fluorine deluted with nitrogen  (1:4) in perfluoro-(N-methylmorpholine) at 20 ^oC results in formation of succinic acid perfluorinated dimethyl eater with the yield of 75%.