Patent ID: 7091364

Claim:
A process for the industrial synthesis of a compound of formula (I): wherein R and R′, which are the same or different, each represent linear or branched (C 1 –C 6 )alkyl, wherein a compound of formula (III): wherein R is as defined hereinbefore, is reacted with a compound of formula (IV): wherein R′ is as defined hereinbefore, in the presence of a catalytic amount of a C 8 –C 10 -type quaternary ammonium compound, and in the presence of potassium carbonate, at reflux with an organic solvent; the reaction mixture is subsequently filtered; the mixture is then concentrated by distillation; a co-solvent is then added, and the reaction mixture is cooled and filtered to yield, after drying of the powder thereby obtained, the compound of formula (I), it being understood that a C 8 –C 10 -type quaternary ammonium compound is a compound of formula (A) or a mixture of compounds of formula (A): R 1 R 2 R 3 R 4 –N +− X (A) wherein R 1 represents (C 1 –C 6 )alkyl, R 2 , R 3 and R 4 , which are identical or different, each represent (C 8 –C 10 )alkyl, and X represents halogen.