Triethylamine → 1-tert-Butyl 3-ethyl (3R)-piperidine-1,3-dicarboxylate

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Reaction Steps

A solution of ethyl N-Boc-(R)-nipecotate-L-tartrate (24) (10.00 g, 32.5 mol) in 50 mL of dioxane and 50 mL of H2O was cooled in ice-water bath and NEt3 (9 mL) was added with stirring. Stirring and cooling were continued while di-tert-butyl dicarbonate (7.44 g, 1.05 eq.) was introduced. The mixture was warmed to room temperature and stirred for 4 h. 100 mL of Ethyl acetate and 20 mL of H2O were added to mixture. The aqueous layer was extracted with ethyl acetate (2×100 mL). The extracts were combined and washed with aqueous potassium carbonate (sat., 2×50 mL), aqueous HCl (5%, 2×50 mL), brine (50 mL), and dried over anhydrous sodium sulfate, filtered and evaporated to give ethyl N-Boc-(R)-nipecotate as a colorless oil 8.37 g (100%).

Provenance & Evidence