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

Participants

Reaction Steps

24.9 g of 1-hydroxybenzotriazole monohydrate and 24.9 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride were added under ice cooling to a 250 mL tetrahydrofuran solution of 25.1 g of (4R)-1-(tert-butoxycarbonyl)-4-hydroxy-L-proline and stirred for 15 minutes. 10.7 g of a 50% dimethylamine aqueous solution was added dropwise over a period of 10 minutes to the reaction mixture, and the reaction mixture was stirred for 15 hours at room temperature. The solvent was distilled off under reduced pressure, after which 100 mL of a saturated sodium hydrogencarbonate aqueous solution was added and extraction was performed with chloroform (50 mL×2). The extract was dried with anhydrous sodium sulfate, the drying agent was filtered off, and the reaction mixture was concentrated under reduced pressure. The residue was purified by column chromatography (silica gel 60N, mobile phase: chloroform/methanol=20/1 to 9/1; v/v) to obtain 26.2 g of the titled compound (colorless solid).

Provenance & Evidence