Diisopropylamine → 1-tert-Butyl 4-methyl 4-(2-nitro-1-phenylethyl)azepane-1,4-dicarboxylate

Participants

Reaction Steps

A cooled (−78° C.) solution of diisopropylamine (667 ul, 4.68 mmol) in THF (dry) (4 ml) was treated with n-BuLi (1.6M in hexanes) (2.93 ml, 4.68 mmol). After 5 minutes, the mixture was allowed to warm to RT and then re-cooled to −78° C. This mixture was added dropwise to a cooled (−78° C.) solution of 1-tert-butyl 4-methyl azepane-1,4-dicarboxylate (step 1) (927 mg, 3.6 mmol) in THF (4 ml). The reaction mixture was stirred at −78° C. for 40 minutes. To this mixture was added (E)-(2-nitrovinyl)benzene (537 mg; 3.6 mmol) in THF (4 ml) and the resulting mixture was allowed to warm slowly to RT. The reaction was quenched with saturated ammonium chloride solution and the mixture was extracted with EtOAc. The combined organic extracts were washed with brine, dried (MgSO4), filtered and concentrated in vacuo. Purification of the crude product by chromatography on silica eluting with iso-hexane/EtOAc followed by 10-100% TBME in iso-hexane afforded the title compound as a diastereomeric mixture.

Provenance & Evidence