Carbon Dioxide → HCID 10957942, compound

Participants

Reaction Steps

To a solution of the title compound of Step A (2.7 g, 7.7 mmol) in tetrahydrofuran (20 mL) under a nitrogen atmosphere cooled to -78° C. was added n-butyllithium (Aldrich, 4.6 mL, 11.5 mmol of a 2.5 M solution in hexane) dropwise while maintaining the temperature below -60° C. After stirring for 2 h, excess carbon dioxide (dry ice) was added. The resulting mixture was allowed to warm to room temperature and was left at room temperature overnight. To this reaction mixture was added hexanes (30 mL), and the mixture was filtered. The solid was added to a mixture of water:methylene chloride (20 mL:20 mL), cooled to about 0° C., and acidified to pH 1 with concentrated hydrochloric acid. The organic layer was separated, and aqueous layer was extracted with diethyl ether (3×25 mL). The combined organic layers were dried (MgSO4), filtered, and concentrated under reduced pressure to about 10 mL. A white solid precipitated and this solid was isolated by filtration to afford the title compound of Step B (1.62 g) as a solid melting at 236-238° C. 1H NMR (Me2SO-d6): δ2.17 (s,3H), 2.68 (m,2H), 2.81 (s,3H), 3.11 (m,2H), 3.50-3.70 (4H), 7.33 (s,1H), 12.78 (s,1H).

Provenance & Evidence