Patent ID: 9688641
Date: 2017-06-27
CPC Classifications: C07D

Claim:
1. Method of preparing an intermediate asymmetric imidazolium salt of formula 1A: in which R1 is an aromatic group, R2 is selected from a secondary cyclic aliphatic alkyl group and a heteroalkyl group, R3 and R4 are selected independently of one another from the group consisting of hydrogen, a halide and an alkyl group, and A− is an anion, comprising the following steps: with one equivalent (1 eq) of a compound of formula 3: in the presence of at least four point five equivalents (4.5 eq) of a Brønsted acid of formula 4: one equivalent (1 eq) of formaldehyde, and at least four point five equivalents (4.5 eq) of the Brønsted acid of formula 4, heating said solution to about 80° C. and then adding the reaction mixture formed in step a.;