Process for the preparation of tubulin inhibitors

摘要

Disclosed is a process for the preparation of 6-[(substituted) phenyl]-triazolopyrimidine dicarboxylic acid salt and as a hydrated salt having the structural formula (I) wherein: R1 is CF3 or C2F5; R2 is H or C1-C3 alkyl; n is an integer of 2, 3, or 4; X is Cl or Br; R3 and R4 are each independently H or C,-C3 alkyl; or R3 and R4 when optionally taken together with the nitrogen atom to which each is attached form a 4 to 6 membered saturated heterocyclic ring having 1-2 nitrogen atoms and 0-1 oxygen atoms or 0-1 sulphur atoms, and optionally substituted with R5; R5 is C,-C3 alkyl; wherein the dotted line is an optional bond.