tert -butylamine
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| General | ||||||||||||||||
| Surname | tert -butylamine | |||||||||||||||
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| Molecular formula | C 4 H 11 N | |||||||||||||||
| Brief description |
colorless liquid with an amine-like odor |
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| properties | ||||||||||||||||
| Molar mass | 73.14 g mol −1 | |||||||||||||||
| Physical state |
liquid |
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| density |
0.70 g cm −3 |
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| Melting point |
−67 ° C |
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| boiling point |
45 ° C |
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| Vapor pressure |
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| solubility |
miscible with water, ethanol and ether |
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| Refractive index |
1.377 (20 ° C) |
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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 | ||||||||||||||||
tert -Butylamine is an organic chemical compound from the group of aliphatic primary amines . It is structural isomer to n -butylamine , iso -butylamine and sec butylamine .
Extraction and presentation
tert -Butylamine is produced industrially by reacting isobutene with ammonia at temperatures of 250-300 ° C and pressures around 300 bar in the presence of an acidic zeolite catalyst .
Zeolites of the pentasil type (z. B. ZSM-5), which essentially consist of aluminosilicates , borosilicates or iron silicates, are preferably used here . This acts according to an ion exchange mechanism as an acidic heterogeneous catalyst , so it can release a proton . The entire reaction takes place in tube bundle reactors , in which a heat transfer medium flows around the tube bundle in order to keep the entire reaction at an almost constant temperature. The catalyst is fixed by a fixed bed . The product is then purified by distillation in rectification columns and unconverted isobutene and ammonia are returned to the reactor.
In the protonation of isobutene which is thermodynamically stable carbenium ion , here the tert -butyl cation is formed. Nucleophilic ammonia then accumulates on this . The positive charge is transferred to the nitrogen of the ammonia molecule, so an ammonium cation is formed . After its deprotonation and the associated regression of the catalyst , tert- butylamine is formed.
In the laboratory, tert- butylamine can be obtained by hydrogenolysis of 2,2-dimethylethyleneimine at temperatures around 60 ° C over Raney nickel catalysts in dioxane as a solvent .
properties
Physical Properties
tert -Butylamine has a relative gas density of 2.52 (density ratio to dry air at the same temperature and pressure ) and a relative density of the vapor-air mixture of 1.59 (density ratio to dry air at 20 ° C and normal pressure). According to Antoine, the vapor pressure function results from log 10 (P) = A− (B / (T + C)) (P in bar, T in K) with A = 3.90694, B = 992.719 and C = −62.727 in the temperature range from 292 to 348 K.
Chemical properties
tert -Butylamine is an easily flammable colorless liquid with an amine-like odor. It is miscible with water, ethanol and ether. The aqueous solutions , however, have a strong alkaline reaction . At a temperature of 20 ° C and a concentration of 100g · l −1 , tert- butylamine has a pH value of 12.1.
Safety-related parameters
The compound forms highly flammable vapor-air mixtures. It has a flash point of −38 ° C. The explosion range is between 1.7% by volume (50 g / m 3 ) as the lower explosion limit (LEL) and 9.2% by volume as the upper explosion limit (UEL). The ignition temperature is 380 ° C. The substance therefore falls into temperature class T2.
use
tert -Butylamine is used as an intermediate for rubber chemicals , pesticides , additives , surfactants , pharmaceuticals , corrosion inhibitors , emulsifiers , plasticizers , etc.
safety instructions
tert -Butylamine is a highly flammable liquid that forms explosive mixtures with air. It is also very volatile. Of tert go butylamine acute and chronic health hazards. The amine is mainly absorbed through the respiratory tract and is corrosive to the eyes , skin and mucous membranes . Inhalation can cause irritation or damage to the lungs. Chronic , inflammatory skin changes were found on repeated contact.
Individual evidence
- ↑ a b c d e f g h i j k l m n o p q r Entry on tert-butylamine in the GESTIS substance database of the IFA , accessed on April 11, 2019(JavaScript required) .
- ↑ a b Entry on Butylamine. In: Römpp Online . Georg Thieme Verlag, accessed on December 26, 2018.
- ↑ Data sheet tert-Butylamine from Sigma-Aldrich , accessed on December 26, 2018 ( PDF ).
- ^ A b 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. 10, doi : 10.1002 / 14356007.a02_001.pub2 .
- ↑ Patent DE19500839 : Process for the production of tert-butylamine. Published on July 18, 1996 , applicant: BASF SE, inventor: Uwe Dingerdissen, Andreas Henne, Juergen Herrmann, Joachim Pfeffinger, Peter Stops.
- ↑ Kenneth N. Campbell, Armiger H. Sommers, and Barbara K. Campbell: tert-Butylamine In: Organic Syntheses . 27, 1947, p. 12, doi : 10.15227 / orgsyn.027.0012 ; Coll. Vol. 3, 1955, p. 148 ( PDF ).
- ^ Osborn, AG; Douslin, DR: Vapor pressure relations of 13 nitrogen compounds related to petroleum in J. Chem. Eng. Data 13 (1968) 534-537, doi : 10.1021 / je60039a024 .
- ^ A b E. Brandes, W. Möller: Safety-related parameters - Volume 1: Flammable liquids and gases , Wirtschaftsverlag NW - Verlag für neue Wissenschaft GmbH, Bremerhaven 2003.
