Cyclopentanol → 1-[2-cyclopentyloxy-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazin-7-yl]-2,2-dimethyl-propan-1-one

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Reaction Conditions

Reaction Steps

A solution of 7-(2,2-dimethyl-propionyl)-5-(2-trimethylsilanyl-ethoxymethyl)-1,5-dihydro-pyrrolo[2,3-b]pyrazin-2-one (0.029 g, 0.082 mmol), 1 mL of tetrahydrofuran, cyclopentanol (0.010 mL, 0.11 mmol), tributylphosphine (0.025 mL, 0.1 mmol), and diisopropyl azodicarboxylate (0.020 mL, 0.10 mmol) under nitrogen was stirred at 65° C. for 17.5 h then allowed to cool. Additional cyclopentanol (0.020 mL, 0.22 mmol), tributylphosphine (0.050 mL, 0.20 mmol), and diisopropyl azodicarboxylate (0.040 mL, 0.21 mmol) were added, and the solution stirred at 65° C. for 2.5 h. The yellow solution was partitioned between 5 mL of water and 5 mL of ethyl acetate. The organic layer was washed with 5 mL of a sat. aq. NaCl solution, dried over MgSO4, filtered and concentrated to a yellow oil. Silica gel chromatography (10% EtOAc/hexanes) afforded 0.017 g (51%) of 1-[2-cyclopentyloxy-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazin-7-yl]-2,2-dimethyl-propan-1-one as a colorless oil.

Provenance & Evidence