Dimethylamine → tert-butyl (2S,4S)-2-(dimethylcarbamoyl)-4-hydroxypyrrolidine-1-carboxylate

Participants

Reaction Steps

9.95 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride was added under ice cooling to a 100 mL tetrahydrofuran solution of 10.0 g of (4S)-1-(tert-butoxycarbonyl)-4-hydroxy-L-proline and 8.77 g of 1-hydroxybenzotriazole monohydrate, and the reaction mixture was stirred for 30 minutes at the same temperature. 15.6 g of a 50% dimethylamine aqueous solution was than added to the reaction solution, after which the reaction mixture was stirred for 1 hour at room temperature. 100 mL of chloroform and 50 mL of a 5% potassium carbonate aqueous solution were added to the reaction solution, liquid separation was performed, the aqueous layer was extracted with chloroform (30 mL×2), and the combined organic layer was washed with 30 mL of saturated brine and dried with magnesium sulfate, after which the drying agent was filtered off and the solvent was distilled off under reduced pressure. The residue thus obtained was subjected to column chromatography (silica gel 60, mobile phase: ethyl acetate/n-hexane=1/1 to 10/0; v/v) to obtain 8.66 g of the titled compound (colorless solid).

Provenance & Evidence