Diisopropylamine → HCID 67051702, compound

Participants

Reaction Steps

To a solution of N,N-diisopropylamine (1.6 mL, 11.2 mmol) cooled to −78° C. in THF (15 mL) was added a 2.5 M solution of n-BuLi in hexane (4.5 mL, 11.2 mmol) dropwise over 5 minutes and the mixture was stirred at this temperature for an addition 15 minutes. 6-methyl-1-(phenylmethyl)piperidine-2-carbonitrile (2.4 g, 11.2 mmol) (prepared using procedures similar to those in Bonin et. al. Tet. Lett. 1982, 23(33), 3369-72) in THF (10 mL) was then added dropwise over 20 minutes and the reaction mixture was stirred for a further minutes. Next a solution of 1,1-dimethylethyl 3-oxoazetidine-1-carboxylate (1.3 g, 7.5 mmoL), prepared using procedures similar to those in Example 3, in THF (10 mL) was added dropwise over 30 minutes. The reaction mixture was gradually warmed to room temperature and allowed to stir overnight. The reaction mixture was quenched with 10% citric acid and extracted with ethyl acetate (3×50 mL). The combined organic layers were washed with water, brine, dried over anhydrous sodium sulfate then filtered and concentrated in vacuo to give crude product as yellow oil. Further purification by flash chromatography (30% ethyl acetate in hexanes) afforded 1,1-dimethylethyl 3-[2-cyano-6-methyl-1-(phenylmethyl)piperidin-2-yl]-3-hydroxyazetidine-1-carboxylate as a pale yellow oil (0.2 g, 7% yield). 1H NMR (400 MHz, CDCl3): 7.17-7.40 (m, 5H), 4.42 (d, 1H), 4.04-4.18 (m, 1H), 3.83-4.00 (m, 1H), 3.70-3.75 (m, 2H), 1.70-1.87 (m, 4H), 1.45 (s, 3H), 1.41 (s, 9H), 1.22-1.26 (m, 1H), 1.13-1.18 (m, 2H); MS (EI) for C22H31N3O3: 386 (MH+).

Provenance & Evidence