An Efficient Scalable Process for the Synthesis of N-Boc-2-tert-butyldimethylsiloxypyrrole

A safe, reliable and scalable process for the preparation of N-Boc-2-tert-butyldimethylsiloxy-pyrrole (TBSOP) is described. In a three-step, one-pot sequence (±)-4-amino-3-hydroxybutyric acid was converted to N-Boc-4-hydroxy-2-pyrrolidinone. This stable crystalline product was isolated by filtration directly from the reaction mixture. Dehydration followed by enolization and silylation produced the target compound without the need for chromatographic purification. The process was demonstrated in the pilot plant to make multikilogram quantities of material in 85% overall yield.