Fig. 5: Synthesis of E3 ligase ligand lenalidomide and linker 18.
From: Discovery of an Aldo-Keto reductase 1C3 (AKR1C3) degrader

Reagents and conditions: (a) tert-butyl bromoacetate, sodium hydride (NaH), THF, 0 °C (30 min) to rt; (b) trifluoroacetic acid (TFA), DCM, rt; (c) SOCl2, DCM, rt; (d) lenalidomide, N-methyl-2-pyrrolidone (NMP), rt.