Triethylamine → Tert-butyl 7-propionyl-2,7-diazaspiro[4.4]nonane-2-carboxylate

Participants

Reaction Steps

To a solution of tert-butyl 3,7-diazaspiro[4.4]nonane-3-carboxylate (127 mg, 0.56 mmol) in anhydrous DCM (1 mL), cooled in an ice water bath was added Et3N (57 mg, 78 μL, 0.56 mmol), followed by the addition of propanoyl chloride (57 mg, 54 μL, 0.62 mmol) as a solution in DCM (0.2 mL). The reaction mixture was stirred for 20 minutes, diluted with DCM and was washed with 1M HCl (×2) and brine (×1). The organic layer was dried over Na2SO4, filtered and concentrated under reduced pressure to yield tert-butyl 3-propanoyl-3,7-diazaspiro[4.4]nonane-7-carboxylate (154 mg, 97%) as an orange oil. 1H NMR (400 MHz, CDCl3) δ 3.73-3.11 (m, 8H), 2.34-2.17 (m, 2H), 1.97-1.70 (m, 4H), 1.46 (s, 9H), 1.16 (t, J=7.4 Hz, 3H). LC/MS m/z 283.5 [M+H]+.

Provenance & Evidence