Diisopropylethylamine → Tert-butyl 7-[5-[bis(tert-butoxycarbonyl)amino]-6-(5-phenyl-1,3,4-oxadiazol-2-yl)pyrazin-2-yl]-3,7-diazaspiro[4.4]nonane-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of tert-butyl N-[5-bromo-3-(5-phenyl-1,3,4-oxadiazol-2-yl)pyrazin-2-yl]-N-tert-butoxycarbonyl-carbamate (70 mg, 0.14 mmol), tert-butyl 3,7-diazaspiro[4.4]nonane-3-carboxylate (31 mg, 0.14 mmol) and DIEA (35 mg, 47 μL, 0.27 mmol) in DMF (1 mL) was heated at 90° C. for 2 h. The reaction mixture was allowed to cool to room temperature and diluted with EtOAc. The organic layer was washed with brine (2×), dried over Na2SO4, filtered and concentrated under reduced pressure. The crude material was purified by flash chromatography using 0-35% EtOAc in hexanes to yield tert-butyl 7-[5-[bis(tert-butoxycarbonyl)amino]-6-(5-phenyl-1,3,4-oxadiazol-2-yl)pyrazin-2-yl]-3,7-diazaspiro[4.4]nonane-3-carboxylate (56 mg, 62%) as a yellow solid. 1H NMR (400 MHz, DMSO-d6) δ 8.15-8.04 (m, 3H), 7.71-7.60 (m, J=7.5 Hz, 3H), 3.74-3.62 (m, 2H), 3.59-3.53 (m, 2H), 3.39 (s, 2H), 2.89 (s, 1H), 2.73 (s, 1H), 2.10-1.99 (m, 2H), 1.98-1.84 (m, 2H), 1.41 (d, J=7.3 Hz, 9H), 1.29 (s, 18H). LC/MS m/z 664.7 [M+H]+.

Provenance & Evidence