Sodium Dithionite → 1-(4-amino-phenyl)-3-[2-(2,6-dioxo-piperidin-3-yl)-1-oxo-2,3-dihydro-1H-isoindol-5-ylmethyl]-urea

Participants

Reaction Conditions

Reaction Steps

To a stirred mixture of 1-((2-(2,6-dioxopiperidin-3-yl)-1-oxoisoindolin-5-yl)methyl)-3-(4-nitrophenyl)urea (150 mg, 0.343 mmol) in EtOH (2 mL) was added sodium dithionite (597 mg, 3.43 mmol) in water (2 mL). The resulting mixture was heated to 60° C. for 20 min at which time LC-MS indicated complete disappearance of nitro starting material. The reaction mixture was combined with the crude product from a separate run and concentrated in mew). The residue was dissolved in minimal DMF and chromatographed on a C-18 preparative HPLC column equipped with mass triggered collection. The desired fractions were combined and concentrated in vacuo to provide 1-(4-amino-phenyl)-3-[2-(2,6-dioxo-piperidin-3-yl)-1-oxo-2,3-dihydro-1H-isoindol-5-ylmethyl]-urea as a pale yellow solid (90 mg, 40% combined average yield from two separate runs): mp: >400° C.; LCMS: MH+=408.

Provenance & Evidence