反应详情

A solution of 0.247 g, (1 mmol) of 2-methyl-1-oxa-5-azaspiro[2,4]-heptane-5-carboxylic acid benzyl ester (Example A9) in dichloromethane (3 mL) is added to a polypropylene flask containing 0.5 mL of hydrogen fluoride-pyridine at −40° C. The reaction is allowed to come to room temperature and stirring is continued for 3 hours. The reaction mixture is poured into an aqueous ice-cold ammonium hydroxide solution (30 mL) and extracted with dichloromethane. The organic layer is dried, filtered and concentrated to afford the title compound (0.267 g). 1H NMR (200 MHz, CDCl3): δ 7.35 (s, 5H), 5.13 (s, 2H), 3.96–3.34 (m, 5H), 2.20–1.98 (m, 3H), 1.33–1.26 (m, 3H).

1. customto come to room temperature
2. extractionextracted with dichloromethane
3. customThe organic layer is dried
4. filtrationfiltered
5. concentrationconcentrated