tert-Butyl 4-[2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-3-oxopiperazine-1-carboxylate → 1-[2-(1,3-Dihydro-4-methyl-1-oxo-5-isobenzofuranyl)ethyl]-2-piperazinone

Participants

Reaction Steps

A solution of tert-butyl 4-[2-hydroxy-2-(4-methyl-1-oxo-1,3-dihydro-2-benzofuran-5-yl)ethyl]-3-oxopiperazine-1-carboxylate (160 mg, 0.41 mmol) in 20 mL of MeOH was treated with Pd(OH)2 (120 mg, 0.21 mmol) was stirred under 40 psi atmosphere of H2 at 60 C. After 18 hrs the solution was filtered through a pad of celite which was subsequently washed with EtOAc. The filtrate was concentrated and the residue was then redissolved in 2 mL of DCM was treated with 4 mL of 4N HCl in dioxane at room temperature. After 2 hours excess solvent was removed and the residue partitioned between 3 mL of 1N NaOH and 10 mL of 10% IPA/Chloroform. The organic layer was collected, dried over magnesium sulfate, filtered and concentrated to give the title product. The free amine was used without further purification. 1H NMR (500 MHz; CDCl3): 7.82 (m, 2H), 5.40 (dd, J=2.3, 8.0 Hz, 1H), 5.27 (s, 1H), 3.74-3.70 (m, 1H), 3.61 (s, 2H), 3.45-3.41 (m, 1H), 3.38-3.34 (m, 1H), 3.26-3.22 (m, 1H), 3.04-3.01 (m, 2H), 2.06 (s, 3H).

Provenance & Evidence