480466-35-1Relevant articles and documents
Regio-selective synthesis of key intermediates of fexofenadine
Kumar, Anil,Bhashkar, Bhuwan,Kumar, Harish,Singh, Gurpreet
, p. 2285 - 2287 (2015)
The present work is focused on improved process of preparation of fexofenadine which is achieved by regio-selective synthesis of intermediate; 1-oxoalkoxy-2-methyl-2-[4-(4-chloro-1-oxobutyl)phenyl]propane. The said intermediate is prepared in good yields and with greater purity wherein the synthesis of side products like 1-oxoalkoxy-2-methyl-2-[3-(4-chloro-1-oxobutyl)phenyl]propane (metaisomer) is reduced to a great amount. The intermediate, 1-oxoalkoxy-2-methyl-2-[4-(4-chloro-1-oxobutyl)phenyl]propane (para-isomer) where, alkyl group is selected from C2-5 carbon chain, is synthesized through preparation of 1-chloro-2-methyl-2-phenylpropane which upon reaction with potassium salt of aliphatic carboxylic acid followed by Friedel-Crafts acylation with 4-chlorobutyrylchloride results into desired intermediate, 1-oxoalkoxy-2-methyl-2-[4-(4-chloro-1-oxobutyl)phenyl]propane and a side impurity, 1-oxoalkoxy-2-methyl-2-[3-(4-chloro-1-oxobutyl)phenyl]propane (meta-isomer) in the ratio of 1:0.09-0.15. The above said mixture can be directly used for the synthesis of fexofenadine and has an advantage of eliminating the purification process at intermediate stage and use of less volume of expensive solvents.
