Method for producing ammonium hexafluorophosphates

1) Process for preparing ammonium hexafluorophosphates of formula 1

• wherein
• R1 and R2 which may be identical or different denote hydrogen or a group selected from among C1-C10-alkyl, C2-C10-alkenyl, C2-C10-alkynyl, C3-C8-cycloalkyl, C4-C8-cycloalkenyl, C6-C8-cycloalkynyl, C6-C10-aryl-C1-C6-alkyl, C6-C10-aryl-C2-C6-alkenyl, C6-C10-aryl-C2-C6-alkynyl, C6-C10-aryl and heterocyclyl, which may optionally be substituted;
• R3 and R4 together with the nitrogen denote a mono-, bi- or tricyclic, saturated or unsaturated carbocyclic group which may contain 4 to 10 carbon centres, wherein optionally one or two of these carbon centres may be replaced by O or S, and which may optionally be substituted;
• characterised in that a compound of formula 2
• wherein R1, R2, R3 and R4 have the meanings given hereinbefore for compound 1 and wherein
• X− may denote an anion with a single negative charge,
• is converted into the compound of formula 1 in a suitable solvent, by reacting with a salt Kat+PF6−, wherein Kat+ denotes a cation selected from among Li+, Na+, K+, Mg2+, Ca2+,
• with the proviso that the compound of formula 1 may not be the compound of formula 1′