Process for the preparation of azidoperfluoroalkanes and N-polyfluoroalkyl azides

A method for preparation of N-perfluoroalkyl- or N-polyfluoroalkyl-substituted triazoles of formula 1

• wherein RF is selected from the group consisting of CnF2n+1, CnFxH2n+1−x, CnFxX2n+1−x or R1CF2CF2, wherein n is an integer in the interval from 1 to 10, x is an integer in the interval from 2 to 20 and
• X is Cl, Br, or I,
• R1 is selected from the group consisting of C1-10 alkyl, ArO, ArS, imidazolyl, benzimidazolyl, or pyrazolyl and Ar is phenyl or substituted phenyl,
• R4 is selected from a group consisting of C1-10 alkyl, XCH2CH2, COOR3, C(CH3)2OH, benzyloxy-C1-4-alkyl, pyridyl, phenyl, and pyridyl or phenyl substituted by a group selected from C1-10 alkyl, F, Cl, Br, I, OR3, NO2, NH2, CF3, wherein R3 is C1-5 alkyl,
• by performing the steps of:
• (A) generation of a synthetic equivalent of polyfluoroalkyl carbanion, said synthetic equivalent having the formula [RF]−, by a method selected from:
• a) activation of trialkyl(polyfluoroalkyl)silane of general formula R33SiRF, wherein R3 is C1-5 alkyl, with a Lewis base which is selected from the group consisting of potassium fluoride, cesium fluoride, tetramethylammonium fluoride, tetrabutylammonium fluoride, sodium carbonate, potassium carbonate, potassium phosphate, sodium acetate, potassium acetate, tetrabutylammonium acetate;
• b) reaction of polyfluoroalkane of general formula RFH with a base which is selected from a group consisting of methyllithium, butyllithium, phenyllithium, Grignard reagent of general formula R3MgX, wherein R3 is C1-5 alkyl, and complexes of these compounds with LiCl;
• or
• c) reaction of halopolyfluoroalkane of general formula RFBr or RFI with metalation reagents, which are selected from a group consisting of methyllithium, butyllithium, Grignard reagent of general formula R3MgX, wherein R3 is C1-5 alkyl, and complexes of these compounds with LiCl,
• at a temperature in the range from −78° C., or from the melting point of the reaction mixture, to +60° C.,
• and
• (B) reaction of an electrophilic azidation reagent of general formula R2—N3,
• wherein R2 is selected from the group consisting of n-C4F9SO2, ArSO2, Br, and I, wherein Ar is phenyl or substituted phenyl,
• with the synthetic equivalent of polyfluoroalkyl carbanion of general formula [RF]− generated in step (A);
• to obtain the azide RF—N3, and then
• performing a cycloaddition reaction of the azide RF—N3 with alkyne of formula 2
• in the presence of copper(I) catalyst at a temperature in the range from −30° C. to the boiling point of the reaction mixture.

A method for preparation of compounds of general formula 3

• wherein RF is selected from the group consisting of CnF2n+1, CnFxH2n+1−x, CnFxX2n+1−x or R1CF2CF2, wherein n is an integer in the interval from 1 to 10, x is an integer in the interval from 2 to 20 and
• X is Cl, Br, or I,
• R1 is selected from the group consisting of C1-10 alkyl, ArO, ArS, imidazolyl, benzimidazolyl, or pyrazolyl and Ar is phenyl or substituted phenyl,
• R4 is selected from a group consisting of C1-10 alkyl, XCH2CH2, COOR3, C(CH3)2OH, benzyloxy-C1-4-alkyl, pyridyl, phenyl, and pyridyl or phenyl substituted by a group selected from C1-10 alkyl, F, Cl, Br, I, OR3, NO2, NH2, CF3, wherein R3 is C1-5 alkyl,
• by performing the steps of:
• (A) generation of a synthetic equivalent of polyfluoroalkyl carbanion, said synthetic equivalent having the formula [RF]−, by a method selected from:
• a) activation of trialkyl(polyfluoroalkyl)silane of general formula R33SiRF, wherein R3 is C1-5 alkyl, with a Lewis base which is selected from the group consisting of potassium fluoride, cesium fluoride, tetramethylammonium fluoride, tetrabutylammonium fluoride, sodium carbonate, potassium carbonate, potassium phosphate, sodium acetate, potassium acetate, tetrabutylammonium acetate;
• b) reaction of polyfluoroalkane of general formula RFH with a base which is selected from a group consisting of methyllithium, butyllithium, phenyllithium, Grignard reagent of general formula R3MgX, wherein R3 is C1-5 alkyl, and complexes of these compounds with LiCl;
• or
• c) reaction of halopolyfluoroalkane of general formula RFBr or RFI with metalation reagents, which are selected from a group consisting of methyllithium, butyllithium, Grignard reagent of general formula R3MgX, wherein R3 is C1-5 alkyl, and complexes of these compounds with LiCl,
• at a temperature in the range from −78° C., or from the melting point of the reaction mixture, to +60° C.,
• and
• (B) reaction of an electrophilic azidation reagent of general formula R2—N3,
• wherein R2 is selected from the group consisting of n-C4F9SO2, ArSO2, Br, and I, wherein Ar is phenyl or substituted phenyl,
• with the synthetic equivalent of polyfluoroalkyl carbanion of general formula [RF]− generated in step (A);
• to obtain the azide RF—N3, and then
• performing a cycloaddition reaction of RF—N3 with alkyne of general formula 4
• and with iodine in the presence of tertiary amine as a base, at a temperature in the range from −30° C. to the boiling point of the reaction mixture.