The structural formula of 1-Boc-4-ethynylpiperidine shows that its molecule contains a piperidine ring with an acetylenic group attached at position 4 and a tert-butoxycarbonyl (Boc) protecting group attached to the nitrogen atom of the piperidine. This structure gives 1-Boc-4-ethynylpiperidine its unique chemical properties and applications.
A solution of dimethyl (1-diazido-2-oxopropyl)phosphonate (323 mg, 1.68 mmol) in methanol (2 mL) was added slowly and dropwise to a stirred mixture of 1-Boc-piperidine-4-carboxaldehyde (358 mg, 1.68 mmol) and potassium carbonate (464 mg, 3.36 mmol) in methanol (16 mL) at 0 °C. The reaction mixture was stirred overnight at room temperature and subsequently filtered and concentrated. The residue was purified by silica gel column chromatography using ethyl acetate/hexane (1:5, v/v) as eluent to afford 1-Boc-4-ynylpiperidine (308 mg, 88% yield) as colorless crystals.LC-MS m/z: 154 [M-Boc+2H]+. (Reference: J. Am. Chem. Soc. 2003, 125, 3714.)
[1] Journal of the American Chemical Society, 2003, vol. 125, # 13, p. 3714 - 3715
[2] Patent: WO2007/97937, 2007, A1. Location in patent: Page/Page column 191
[3] Patent: WO2008/156739, 2008, A1. Location in patent: Page/Page column 222
[4] Tetrahedron Letters, 2006, vol. 47, # 11, p. 1729 - 1731
[5] Medicinal Chemistry Research, 2018, vol. 27, # 11-12, p. 2437 - 2445
