Carbon Dioxide → HCID 19047189, compound

Participants

Reaction Conditions

Reaction Steps

8.20 g (0.041 mol) of the title compound of Step B was added to 200 mL of tetrahydrofuran under nitrogen. The solution was cooled to about -65° C. and 21 mL (0.053 mol) of 2.5M n-butyllithium was added dropwise while keeping the reaction temperature below -55° C. After stirring for 1 h, an excess of solid CO2 was added in portions and the mixture was allowed to warm to room temperature over 2 hr. The mixture was then diluted with 150 mL of hexane and the precipitate was collected by filtration. The precipitate was added to a mixture of 300 mL of water and 300 mL of methylene chloride, cooled to about 0° C., and then acidified to pH 1 with concentrated hydrochloric acid. The layers were separated and the aqueous layer was extracted with diethyl ether (2×300 mL). The combined organic layers were dried (MgSO4), filtered, and evaporated to dryness to yield 6.36 g of the title compound of Step C as a solid melting at 176°-178° C. 1H NMR (DMSO-d6): δ 1.3 (s,6H), 1.95 (m,2H), 2.6 (s,3H), 3.08 (m,2H), 12.7 (br s, 1H).

Provenance & Evidence