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N-Benzylpiperidine:
Piperidine, 1-(phenylmethyl)-; (2905-56-8)
Experiment:
To 1-benzylpyridinium chloride (415 mg, 2 mmol), Na2S2O4 (1750 mg, 10 mmol) and Na2CO3 (640 mg, 6 mmol) was added water (25 mL). Some gas evolution was observed during the dissolution and the resulting yellowish clear solution rapidly discoloured to completely colourless. This solution was refluxed for 5 h (without reaction progress monitoring), cooled and extracted with ethyl acetate (10 mL). The extract showed one major peak on HPLC and a little impurity on the more polar side. A HPLC run with a bit of toluene added as an internal standard confirmed that no reductive cleavage of benzylpyridinium to toluene occurred. TLC also showed one strong spot and some minor impurities. Part of the extract was rotavaped and analysed by NMR, which confirmed that the major product is N-benzylpiperidine (see Org. Synth. for 1H and 13C NMR spectral data of benzylpiperidine). NMR fits well and all the DEPT135 peaks are present also in the cited 13C NMR. The IR spectra also matched.
http://orgsyn.org/demo.aspx?prep=v83p0217
1H NMR pdf (300 MHz, CDCl3) δ: 1.42 (m, 2 H), 1.56 (m, 4 H), 2.36 (m, 4 H), 3.46 (s, 2 H), 7.31–7.23 (m, 5 H); http://orgsyn.org/content/pdfs/Spectrum/v83p0217_H_note9.pdf
13C NMR (75 MHz, CDCl3) δ: 24.3, 25.9, 54.4, 63.8, 126.7, 127.9, 129.0, 138.6;
IR (thin film) 3062, 2934, 2852, 2684, 1493, 1369, 1154, 1113 cm−1;
EIMS m/z: 91(100), 175(95), 98(92), 84(91), 65(75), 176(58). Purity (>99.5%) was assessed by Gas Chromatography (GC) with a retention time (Rt) of 11.16 min: (Agilent 19091Z-413E, HP-1 Methyl siloxane, 0.32 mm × 30 m × 0.25 µm; temperature 50 °C, ramp 10°/min to 350 °C).
References and Notes
- a) Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan; email: fujitak@kagaku.mbox.media.kyoto-u.ac.jp b) email: yama@kagaku.mbox.media.kyoto-u.ac.jp c) Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, email: curran@pitt.edu
- Fujita, K.; Fujii, T.; Yamaguchi, R. Org. Lett. 2004, 6, 3525.
- White, C.; Yates, A.; Maitlis, P. M. Inorg. Synth. 1992, 29, 228.
- Felpin, F.-X.; Lebreton, J. Eur. J. Org. Chem. 2003, 3693.
- Nakamura, I.; Yamamoto, Y. Chem. Rev. 2004, 104, 2127.
- Murahashi, S.-I.; Kondo, K.; Hakata, T. Tetrahedron Lett. 1982, 23, 229.
- Tsuji, Y.; Huh, K.-T.; Ohsugi, Y.; Watanabe, Y. J. Org. Chem. 1985, 50, 1365.
- Felföldi, K.; Klyavlin, M. S.; Bartók, M. J. Organomet. Chem. 1989, 362, 193.
- Abbenhuis, R. A. T. M.; Boersma, J.; van Koten, G. J. Org. Chem. 1998, 63, 4282.
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