Ethyl Bromide → HCID 12709313, compound

Participants

Reaction Steps

To a stirred solution of (2S,4S)-4-hydroxy-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester (1.0 eq, 5.0 g) in ethyl acetate (250 mL) was added dicyclohexamine (2.0 eq, 8.62 mL) and the reaction stirred for 5 mins during which time a white precipitate formed. Part of the ethyl acetate was evaporated and the slurry left to stand for 30 mins, then filtered and washed with diethyl ether (30 mL). The filtrate was dried briefly under high vacuum and then resuspended in anhydrous DMF (50 mL). The reaction mixture was then treated with ethyl bromide (4.0 eq, 6.46 mL) and stirred in a sealed flask for 18 hours. TLC and MS revealed that the reaction was complete. The reaction mixture was filtered and washed with ethyl acetate (2×20 mL). The filtrate was then evaporated to dryness, the residue taken up in ethyl acetate (50 mL) and the organic layer washed once with water and once with brine, dried over sodium sulfate, filtered and evaporated to yield a colourless oil (4.87 g; 87%). The crude product was used without further purification. MS (ESI): m/z=204.1 [M+H-Boc]+.

Provenance & Evidence