Pempidine

From Infogalactic: the planetary knowledge core
Jump to: navigation, search
Pempidine
File:Pempidine.png
Systematic (IUPAC) name
1,2,2,6,6-pentamethylpiperidine
Identifiers
CAS Number 79-55-0
PubChem CID: 6603
ChemSpider 6353
UNII N5I18JI9D6 YesY
ChEMBL CHEMBL1617409
Chemical data
Formula C10H21N
Molecular 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

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]

Toxicology

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]

Chemistry

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.

References

  1. A. Spinks and E. H. P. Young (1958) Nat. 181 1397
  2. G. E. Lee et al. (1958) Nat. 181 1717.
  3. 3.0 3.1 3.2 3.3 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. 5.0 5.1 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.

External links