| abstract |
A process is provided for preparing a dipeptidyl peptidase IV inhibitor of the structure, wherein, is treated with TFAA in isopropyl acetate to protect the tertiary hydroxyl group as a trifluoroacetate group to form 4, which is converted to acid chloride compound 5, using Vilsmeier reagent or other chloro reagent and coupled with compound 6 in a heterogeneous mixture of ethyl acetate and aqueous bicarbonate to give compound 7, The N, O-bis(trifluoroacetyl) groups of compound 7 are deprotected to give free base compound 10. |