Sodium ethoxide → 7,7-dimethyl-3,4,7,8-tetrahydro-2H-cyclopenta[4,5]pyrrolo[1,2-a]pyrazin-1(6H)-one

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Reaction Conditions

Reaction Steps

A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer and nitrogen inlet was purged with nitrogen and charged with crude 1-(2-aminoethyl)-5,5-dimethyl-1,4,5,6-tetrahydrocyclopenta[b]pyrrole-2-carboxylate hydrochloride 107d (˜18 mmol), sodium ethoxide (6.2 g, 92 mmol) and ethanol (120 mL). The mixture was stirred at 55° C. over night. After that time, the reaction mixture was concentrated under reduced pressure and the residue was partitioned between ethyl acetate (200 mL) and water (100 mL). The solution was filtered. The solid was washed with ethyl acetate (15 mL) to give 850 mg of desired product 107e. The organic layer was separated, and the aqueous layer was extracted with ethyl acetate (2×100 mL). The combined organic layers were dried over sodium sulfate and concentrated under reduced pressure to near dryness. The solution was filtered and the solid (1.44 g) was washed with ethyl acetate (15 mL). The combined solids were dried under vacuum a afford 61% yield (2.3 g) of 107e.

Provenance & Evidence