Diisopropylamine → 4-Phenyl-2,8-diazaspiro[4.5]decan-1-one

Participants

Reaction Conditions

Reaction Steps

An LDA (14 mmol) solution was prepared by treating diisopropylamine (1.37 g, 14 mmol) with BuLi (1.6 M, 8.5 mL, 14 mmol) at −78° C. in dry THF (10 mL) under argon and allowing to warm up to −20° C. This solution was then cooled to −60° C. added to a solution of 1-benzyl-piperidine-4-ethyl carboxylate (3.05 g, 12 mmol) in THF (8 mL) at −60° C. and allowed to warm up to −40° C. over 1 h whereupon a solution of trans-beta-nitrostyrene (1.93 g, 13 mmol) in THF (8 mL) was added dropwise. The reaction mixture was allowed to warm up to room temperature over 1 h and then quenched with ammonium chloride (saturated, 40 mL) and the product extracted with ethyl acetate (2×40 mL). The combined organic extracts were then washed with brine, dried over sodium sulfate, filtered and evaporated. Purification by chromatography on silica gel eluting with DCM:MeOH (9:1) afforded the title compound (4.1 g, 84%) as a light yellow gum. MS: m/e=397.4 (M+H).

Provenance & Evidence