| abstract |
The present invention relates to a process for the preparation of a compound of formula (I) or a pharmaceutically acceptable salt thereof:nâ–ˇnWherein R represents one or more groups independently selected from the group consisting of fluorine, chlorine, bromine, and iodine, and the process comprises cyclopropanation of a compound of formula (II) with ethyl or ethyl sulphate:nâ–ˇnWherein X is chlorine, bromine, iodine or trifluoromethanesulfonate (CF3SO3) or a ketone group, wherein R is as defined above and G is -CN or -COOR2, wherein R2 is a C1-C4 straight or branched alkyl chain . |