1-methylpiperidine
Structural formula | |||||||||||||||||||
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General | |||||||||||||||||||
Surname | 1-methylpiperidine | ||||||||||||||||||
other names |
N -methylpiperidine |
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Molecular formula | C 6 H 13 N | ||||||||||||||||||
Brief description |
colorless liquid with an amine-like odor |
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properties | |||||||||||||||||||
Molar mass | 99.18 g mol −1 | ||||||||||||||||||
Physical state |
liquid |
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density |
0.82 g cm −3 (20 ° C) |
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Melting point |
−103.23 ° C |
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boiling point |
approx. 107 ° C |
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Vapor pressure |
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solubility |
miscible with water |
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Refractive index |
1.438 (20 ° C) |
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safety instructions | |||||||||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C |
1-methylpiperidine ( IUPAC ) is an organic-chemical compound from the group of cyclic , tertiary amines . The compound serves as a starting material for organic syntheses and for the production of catalyst systems .
Extraction and presentation
For the industrial production of 1-methylpiperidine, 5-amino-1-pentanol is used with methanol at temperatures of 180-230 ° C and pressures of 70-120 bar in the presence of copper oxide and sodium oxide - catalysts based on aluminum oxide (Al 2 O 3 ) are carried to.
The complete reaction takes place in the liquid phase in a continuous tube or tube bundle reactor . The catalyst is arranged as a fixed bed and the reaction mixture can flow against it from below or above. The product is purified and worked up by multi-stage distillation in rectification columns .
properties
Physical Properties
1-Methylpiperidine has a relative gas density of 3.42 (density ratio to dry air at the same temperature and pressure ) and a relative density of the vapor-air mixture of 1.10 (density ratio to dry air at 20 ° C and normal pressure ). The dynamic viscosity at a temperature of 20 ° C is 5 mPa · s.
Chemical properties
1-Methylpiperidine is a highly flammable, colorless liquid with an amine-like odor. The compound belongs to the substance class of cyclic, tertiary amines and can also be understood as a nitrogen heterocycle . N -Methylpiperidine is miscible with water and, as an aqueous solution, has a strongly alkaline reaction . An aqueous solution of the compound (concentration: 100 g / l) has a pH of 12 at a temperature of 20 ° C. With acids and oxidizing agents , sometimes violent reactions occur.
use
1-Methylpiperidine is used, among other things, as an intermediate in the production of a growth regulator for cotton plants . It is also used as a solvent itself and in the manufacture of other chemicals. 1-Methylpiperidine is also used as a reagent for the synthesis of catalyst systems based on ruthenium . It is also used in the preparation of antibacterial imidazolium , pyrrolidinium and piperidinium salts .
safety instructions
The vapors of 1-methylpiperidine form explosive mixtures with air. The substance is mainly absorbed through the respiratory tract . Furthermore, good absorption through the skin is assumed. Ingestion or exposure leads to acute irritating effects on the mucous membranes of the eyes and the respiratory tract and on the skin. Chronic information is not available for humans. Reproductive toxicity could not be demonstrated in an animal experiment, but no further values are available for humans. No detailed information is available on mutagenicity and carcinogenicity . 1-Methylpiperidine has a lower explosion limit (LEL) of 1.1% by volume and an upper explosion limit (UEL) of 9.9% by volume. The ignition temperature is 205 ° C. The substance therefore falls into temperature class T3. With a flash point of 3 ° C, 1-methylpiperidine is considered highly flammable. The connection is also classified as highly hazardous to water.
See also
Web links
Individual evidence
- ↑ a b c d e f g h i j k l m Entry on 1-methylpiperidine in the GESTIS substance database of the IFA , accessed on February 26, 2020(JavaScript required) .
- ↑ Data sheet 1-Methylpiperidine from Sigma-Aldrich , accessed on February 26, 2020 ( PDF ).
- ↑ Entry on 1-methylpiperidine in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on March 22, 2020. Manufacturers or distributors can expand the harmonized classification and labeling .
- ↑ a b Patent EP2582669B1 : Process for the production of a cyclic tertiary methylamine. Published on October 7, 2015 , applicant: BASF SE, inventor: Christof Wilhelm Wigbers, Johann-Peter Melder, Bernd Stein, Harald Meissner.
- ↑ Peter Roose, Karsten Eller, Erhard Henkes, Roland Rossbacher, Hartmut Höke: Amines, Aliphatic. In: Ullmann's Encyclopedia of Industrial Chemistry . Wiley ‐ VCH Verlag GmbH & Co. KGaA., September 30, 2015, p. 25, doi : 10.1002 / 14356007.a02_001.pub2 .