| abstract |
A process for the preparation of a compound of formula (I), or a salt thereof, both as the as individual isomer and as mixtures thereof,n nwherein each of A and B is independently aryl or heteroaryl optionally substituted with 1 to 4 substituents; and R and R 1 , which can be the same or different, are hydrogen, C 1 -C 6 alkyl or an amino-protecting group; comprising the reaction of a compound (II)n nwherein A and B are as defined above, with a compound (III)n nwherein each of R and R 1 is independently C 1 -C 6 alkyl or an amino-protecting group; and X is a leaving group; in the presence of a basic agent; and, if desired the conversion of a compound (I) to another compound (I); and/or, if desired, the separation of an isomeric mixture of a compound (I) into the individual isomers; and/or, if desired, the conversion of a compound (I) to a salt thereof. |