Systematic (IUPAC) name
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Chemical data
Formula C10H21N 
Mol. mass 155.28 g/mol

Pempidine is a ganglion-blocking drug, first reported in 1958 by two research groups working independently, and introduced as an oral treatment for hypertension.[1][2]


  • Pharmacology 1
  • Toxicology 2
  • Chemistry 3
  • References 4
  • External links 5


Reports on the "classical" pharmacology of pempidine have been published.[3][4] The Spinks group, at ICI, compared pempidine, its N-ethyl analogue, and mecamylamine in considerable detail, with additional data related to several structurally simpler compounds.[3]


LD50 for the HCl salt of pempidine in mice: 74 mg/kg (i.v.); 125 mg/kg (i.p.); 413 mg/kg (p.o.).[3]


Pempidine is an aliphatic, sterically hindered, cyclic, tertiary amine, which is a weak base: in its protonated form it has a pKa of 11.25.[5]

Pempidine is a liquid, b.p. 187-188°; d = 0.858 g/cm3.[3]

Two early syntheses of this compound are those of Leonard and Hauck,[6] and Hall.[5] These are very similar in principle: Leonard and Hauck reacted phorone with ammonia, to produce 2,2,6,6-tetramethyl-4-piperidone,[7] which was then reduced by means of the Wolff-Kishner reaction to 2,2,6,6-tetramethylpiperidine; this secondary amine was then N-methylated using methyl iodide and potassium carbonate.[8]

Hall's method involved reacting acetone with ammonia in the presence of calcium chloride to give 2,2,6,6-tetramethyl-4-piperidone, which was then reduced under Wolff-Kishner conditions, followed by N-methylation of the resulting 2,2,6,6-tetramethylpiperidine with methyl p-toluenesulfonate.


  1. ^ A. Spinks and E. H. P. Young (1958) Nat. 181 1397
  2. ^ G. E. Lee et al. (1958) Nat. 181 1717.
  3. ^ a b c d A. Spinks et al. (1958) Br. J. Pharmacol. Chemother. 13 501-520.
  4. ^ D. F. Muggleton and H. W.Reading (1959) Br. J. Pharmacol. Chemother. 14 202
  5. ^ a b H. K. Hall (1957) J. Am. Chem. Soc. 79 5447-5451.
  6. ^ N. J. Leonard and F. P. Hauck (1957) J. Am. Chem. Soc. 79 5279-5292.
  7. ^ The "trivial" name of this compound is triacetonamine.
  8. ^ The boiling point of 147° given by these authors for their N,2,2,6,6-pentamethylpiperidine (pempidine) is significantly below the range of ~ 182-188° reported by other chemists.

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