[2591-86-8]  · C6H11NO  · N-Formylpiperidine  · (MW 113.18)

(formylating agent for certain organometallics;1 reacts with sulfur tetrafluoride/KF to give N-trifluoromethylpiperidine;2 easily converted to reactive chloromethyleneiminium ions3)

Physical Data: bp 222 °C; d 1.09 g cm-3.

Form Supplied in: liquid; widely available.

Analysis of Reagent Purity: IR, NMR.

Handling, Storage, and Precautions: toxic; irritant.

N-Formylpiperidine (1) is a good formylating agent for certain organometallics. Carbaldehydes can be obtained by reacting (1) with organolithium or Grignard reagents (eq 1).1

N-Trifluoromethylpiperidine will result on reaction of (1) with Sulfur Tetrafluoride and Potassium Fluoride (eq 2).2

Chloromethyleneiminium ions with different counterions can be easily prepared from (1).3 The chloromethyleneiminium ion generated from (1) reacts with thioamides to give various products depending on the reaction conditions (eqs 3-5).4,5 N,N-Disubstituted thioamides undergo condensation to give thioenamides (2) (eq 3).4 Under similar reaction conditions, primary thioamides yield either the nitrile (3) (eq 4) or the salt (4) (eq 5).5

Related Reagents.

N,N-Dimethylformamide; N-Methylformanilide; N-Methyl-N-(2-pyridyl)formamide.

1. (a) Olah, G. A.; Arvanaghi, M. AG(E) 1981, 20, 878. (b) Hartman, G. D.; Halozenko, W.; Phillips, B. JOC 1985, 50, 2427. (c) Hartman, G. D.; Halozenko, W.; Phillips, B. JOC 1986, 51, 142. (d) Olah, G. A.; Arvanaghi, M. OS 1986, 64, 114. (e) Pflieger, P.; Mioskowski, C.; Salaun, J. P.; Weissbart, D.; Durst, F. TL 1988, 29, 6775. (f) Radinov, R.; Chanev, C.; Khaimova, M. JOC 1991, 56, 4793. (g) Flouzat, C.; Savelon, L.; Guillaumet, G. S 1992, 842.
2. Dmowski, W.; Kaminski, M. JFC 1983, 23, 207.
3. Liebscher, J.; Knoll, A.; Hartmann, H.; Anders, S. CCC 1987, 52, 761.
4. Liebscher, J.; Abegaz, B. S 1982, 769.
5. Liebscher, J. S 1982, 1084.

Daniel L. Comins & Sajan P. Joseph

North Carolina State University, Raleigh, NC, USA

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