Trifluoroacetic acid → 2-Oxa-7-azaspiro[3.5]nonane

反応式

FC(F)(F)C(O)=O.[CH2:8]1[C:11]2([CH2:16][CH2:15][N:14](C(OC(C)(C)C)=O)[CH2:13][CH2:12]2)[CH2:10][O:9]1.C(=O)([O-])O.[Na+]>ClCCl>[CH2:8]1[C:11]2([CH2:16][CH2:15][NH:14][CH2:13][CH2:12]2)[CH2:10][O:9]1

参加物

実験手順

Trifluoroacetic acid (5 mL) was added to a solution of 1,1-dimethylethyl 2-oxa-7-azaspiro[3.5]nonane-7-carboxylate (Description 69, 80 mg, 0.625 mmol) in dichloromethane (15 mL) and the mixture was stirred at room temperature for 3 hours. Saturated aqueous sodium hydrogen carbonate (3 mL) and dichloromethane (5 mL) were added and the layers were separated. The aqueous layer was extracted with dichloromethane (3×3 mL) and the combined organic fractions were poured onto an SCX cartridge (Varian Bond Elut™; 10 mL/500 mg). The cartridge was washed with methanol (4×2 mL), then eluted with methanolic ammonia (2M, 2×2 mL). The solvent was evaporated under reduced pressure to give the title compound as a colorless solid (8 mg, 17%). m/z (ES+) 128 (M+1).