Process for the preparation of fibrates
A process for the preparation of fibrates of formula I in which R 1 is a halogen atom, a 2,2-dichloro-cyclopropyl group, a (4-chlorophenyul)-hydroxymethyl group, a-4-chlorobenzoyl group or a 2-(4-chlorobenzamido)-ethyl group, and R 2 is hydrogen or a C 1 -C 4 alkyl group.
1. A process for the preparation of fibrates of formula (I)
wherein R 1 as a halogen atom, a 2,2-dicloro-cyclopropyl group, a (4-chlorophenyl)-hydroxyethyl group, a 4-chlorobenzoyl group or a 2-(4-chlorobenzyamido)-ethyl group, and R 2 is hydrogen or a C 1 -C 4 group, which process comprises reacting an alkyl 2-bromo-2-methyl-propionate of formula (II)
wherein R 2 is a defined above,
with a substituted phenol of formula (III)
wherein R 1 is defined as above;
said reaction being conducted in the presence of potassium bi-carbonate and a solvent selected from C 1 -C 4 alcohols and ketones at a temperature ranging from room temperature to 100° C.; and recovering the reaction product directly from the reaction mixture by solvent evaporation followed by crystallization.
2. A process as claimed in claim 1 for the preparation of fenfibrate.
3. A process as claimed in claim 1 wherein the reaction solvent is isopropanol.