Selective Debenzylation of N-Benzyloxypyrazinones in Flow

By using flow technology, we have succeeded in delivering a reproducible methodology for the selective debenzylation of O-benzyl protected cyclic hydroxamates, with a potential of scaling up from milligram scale to gram scale via suitable flow operations. This solved reproducibility problems experienced earlier using batch reaction conditions and finally allowed the efficient, safe, and reproducible synthesis of a library of 28 N-hydroxypyrazin-2(1H)-one analogues.