N-Boc Sitagliptin Acid impurity

N-Boc Sitagliptin Acid impurity is a tert-butyloxycarbonyl-protected intermediate derived from Sitagliptin synthesis. It features a pyrazine ring fused to a substituted tetrahydropyridine core, with a trifluoromethyl group and a carboxylic acid moiety. The Boc-protected amino functionality at the pyrazine nitrogen distinguishes it from the parent drug, which undergoes deprotection during final API synthesis. This impurity arises from incomplete removal of the Boc group during Sitagliptin manufacturing. It serves as a critical HPLC reference standard for monitoring deprotection efficiency and impurity profiling in quality control workflows.