Formamide

Structural formula
General
Surname	Formamide
other names	Methanamide Formic acid amide
Molecular formula	CH 3 NO
Brief description	colorless to yellowish liquid with an ammonia-like odor
External identifiers / databases
CAS number 75-12-7 EC number 200-842-0 ECHA InfoCard 100,000,766 PubChem 713 Wikidata Q283917
properties
Molar mass	45.04 g mol −1
Physical state	liquid
density	1.13 g cm −3 (20 ° C)
Melting point	2 ° C
boiling point	210 ° C
Vapor pressure	0.08 hPa (20 ° C)
solubility	completely miscible with water
Refractive index	1.4472 (20 ° C)
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary danger H and P phrases H: 351-360D-373 P: 201-314
Authorization procedure under REACH	of particular concern : toxic for reproduction ( CMR )
MAK	Switzerland: 10 ml m −3 or 18 mg m −3
Toxicological data	5580 mg kg −1 ( LD 50 ,  rat ,  oral ) 17,000 mg kg −1 ( LD 50 ,  rabbit ,  transdermal )
Thermodynamic properties
ΔH f 0	−254.0 kJ / mol
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

Formamide is the amide of formic acid and the simplest carboxamide.

Manufacturing

Formamide is produced on an industrial scale by reacting carbon monoxide with ammonia . Here, the carbon monoxide initially reacts with methanol to form methyl formate . This is then reacted with ammonia, the methanol released being returned to the first reaction stage.

Formamide can be obtained in small quantities in the production of amphetamine .

properties

Physical Properties

At room temperature the substance is a colorless and odorless liquid. It is hygroscopic and acts as a solvent and reducing agent.

Chemical properties

Formamide is unstable at temperatures above 185 ° C. At 185 ° C it splits purely thermally (without catalysts) into carbon monoxide , carbon dioxide and ammonia , without hydrogen cyanide being detected. At 220 ° C the formation of ammonia is increased, while hydrogen cyanide is also formed. The formation of ammonium carbonate , ammonium hydrogen carbonate and ammonium carbamate increases with increasing temperature, the latter being particularly easily formed from anhydrous ammonia with carbon dioxide. With prolonged thermal exposure, a black, insoluble solid forms, which is identical to polymeric hydrocyanic acid and could be isolated from the purine . This polymer (residue) also forms from 360 ° C hydrocyanic acid and isocyanic acid . In addition, isocyanuric acid is formed from formamide through thermal stress.

To produce hydrogen cyanide from formamide by splitting off water, catalysts are used which accelerate the desired reaction while the thermal splitting, which leads to undesirable products, is suppressed. For this purpose, heated metal surfaces - made of brass or iron  - are suitable, which are coated with a metal oxide layer, for example made of zinc, aluminum, magnesium, chromium or tin oxides, or sintered molded bodies made of aluminum oxide and silicon dioxide or those made of chromium-nickel Stainless steel . From temperatures between 300 and 600 ° C and when gaseous formamide is used, dehydrogenating metal catalysts made of steel are also suitable (based on iron with proportions of chromium and nickel, suitable steel grades include 1.4541, 1.4571, 1.4573, 1.4580, 1.4401, 1.4404, 1.4435 , 2.4816, 1.3401, 1.4876, 1.4762) with a large internal surface for the catalytic conversion and show high selectivities and conversions (> 90%) with a service life of 500 to 8000 hours.

Occurrence

Formamide is the simplest amide and is found everywhere ( ubiquitously ) in the universe. It was detected in the comets Hale-Bopp and Hyakutake as well as in the galactic center of Sagittarius A * and in general in interstellar matter .

use

Formamide is mainly used for the industrial synthesis of formic acid and ammonium sulfate through reaction with sulfuric acid. It is also processed into hydrogen cyanide by pyrolysis in the formamide vacuum synthesis. It is also used as an intermediate in the manufacture of medicinal products and fungicides, such as theophylline or theobromine, or as a catalyst in carbonylation reactions.

Formamide is a commonly used solvent , for example for paints, certain polymers and stains, and for ink in felt-tip pens .

The most important producer of formamide is BASF with a production capacity of 100,000 tons per year (as of 1998), the majority of the formamide produced is further processed directly on site.

Individual evidence

1. ↑ ^{a b c d e f g h i j} Entry on formamide in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .
2. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-262.
3. ↑ Entry on Formamide in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
4. ↑ Entry in the SVHC list of the European Chemicals Agency , accessed on July 16, 2014.
5. ↑ Swiss Accident Insurance Fund (Suva): Limit values ​​- current MAK and BAT values (search for 75-12-7 or formamide ), accessed on November 2, 2015.
6. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-20.
7. ↑ Hans-Jürgen Arpe: Industrial Organic Chemistry: Significant preliminary and intermediate products. ISBN 978-3-527-31540-6 , p. 49.
8. ^ ^{A b} F. Cataldo, E. Lilla, O. Usrini, G. Angelini: TGA-FT-IR Study of pyrolysis of poly (hydrogen cyanide) synthesized from thermal decomposition of formamide. Implications in cometary emissions. In: Journal of Analysis and Applied Pyrolysis . 87, 2010, pp. 34-44, doi : 10.1016 / j.jaap.2009.10.002 .
9. ↑ Patent US7294326 : Dehydration of formamide to produce hydrocyanic acid. Published June 2, 1936 . ‌
10. ↑ Patent US2042451 : Hydrocyanic acid consisting of formamide. Released May 25, 2006 . ‌
11. ↑ Patent WO2004050587A2 : Hydrocyanic acid from formamide. Filed December 3, 2003 , published June 17, 2004 . ‌
12. ↑ Patent EP1791787 : Process for the production of hydrogen cyanide . Published on April 15, 2010 . ‌
13. ↑ Patent EP1575870B1 : Hydrocyanic acid from formamide. Published on October 20, 2010 . ‌
14. ↑ R. Saladino, C. Crestini, S. Pino, G. Costanzo, E. Di Mauro: formamides and the origin of life . In: Physics of Life Reviews . 9, 2012, pp. 84-104, doi : 10.1016 / j.plrev.2011.12.002 , PMID 22196896 .
15. ↑ ^{a b c} Hansjörg Bipp, Heinz Kieczka: Formamides. In: Ullmann's Encyclopedia of Industrial Chemistry . Wiley-VCH, Weinheim 2012 doi : 10.1002 / 14356007.a12_001.pub2 .