Malononitrile

Structural formula
General
Surname	Malononitrile
other names	Dicyanomethane; Malodinitrile; Malonitrile; Malononitrile; Propandinitrile; Methylenedinitrile; Cyanoacetonitrile;
Molecular formula	C 3 H 2 N 2
Brief description	colorless to yellow solid
External identifiers / databases
EC number	203-703-2
ECHA InfoCard	100.003.368
PubChem	8010
ChemSpider	13884495
Wikidata	Q419572
properties
Molar mass	66.06 g mol −1
Physical state	firmly
density	1.049 g cm −3
Melting point	32 ° C
boiling point	220 ° C
Vapor pressure	1 h Pa (50 ° C)
solubility	easily in water (133 g l −1 at 20 ° C); soluble in ethanol and diethyl ether ;
Refractive index	1.4146 (34 ° C)
safety instructions
H and P phrases	H: 300-311-331-319-317-410
	P: 273-280-304 + 340-305 + 351 + 338-311
Toxicological data	25 mg kg −1 ( LD 50 , rat , oral )
Thermodynamic properties
ΔH f 0	186.4 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

Malononitrile , also propanedinitrile , is a chemical compound from the class of nitriles having the formula CH ₂ (CN) ₂ . Malononitrile is relatively acidic with a p K _s value of 11 in water. Malononitrile can therefore react in a Knoevenagel condensation , for example to produce 2-chlorobenzylidene-malononitrile .

Extraction and presentation

Malononitrile can be produced from chlorocyanoacetylene and ammonia . On an industrial scale, malononitrile is produced by reacting acetonitrile with cyanogen chloride at over 700 ° C. Other possibilities for production start from (2-cyano- N- alkoxy) -acetimidoyl halides, temperatures between 500 and 1000 ° C. also being required.

properties

Malonitrile is a flammable, colorless solid that is easily soluble in water. It decomposes from a temperature of 130 ° C, producing hydrogen cyanide , nitrogen oxides , carbon monoxide and carbon dioxide and an explosion is possible. The heat of decomposition determined by DSC is −108 kJ · mol ⁻¹ or −1650 kJ · kg ⁻¹ . At lower temperatures, contact with strong bases can lead to violent polymerization, which can also be explosive.

use

In chemistry, malononitrile is a starting material for the Gewald reaction , in which the nitrile condenses with a ketone or aldehyde in the presence of elemental sulfur and a base to form 2-aminothiophenes . Furthermore, malononitrile plays an important role in the synthesis of a variety of pharmaceutical and agrochemical active ingredients. Malononitrile is a starting material for the production of CS gas .

Synthesis of 2-chlorobenzylidenemalonic acid dinitrile (CS gas)

Individual evidence

↑ ^a ^b ^c Entry on malononitrile. In: Römpp Online . Georg Thieme Verlag, accessed on July 5, 2016.
↑ ^a ^b ^c ^d ^e ^f ^g ^h Entry on malonitrile in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .
↑ 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. 3-322.
↑ Entry on malononitrile 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 .
↑ Data sheet malononitrile (PDF) from Merck , accessed on January 19, 2011.
↑ 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. 5-23.
↑ Evans pK _a table (PDF; 245 kB)
↑ Peter B. Sargeant: Fluorocyclopropanes. I. Preparation and nuclear magnetic resonance spectra. In: Journal of Organic Chemistry. 35 (3), 1970, pp. 678-682.
^ Process for the preparation of malononitrile
↑ T. Grewer, O. Klais: Exothermic decomposition - investigations of the characteristic material properties. (= Humanization of working life. Volume 84). VDI-Verlag, Düsseldorf 1988, ISBN 3-18-400855-X , p. 8.
↑ Bretherick's Handbook of Reactive Chemical Hazards. 6th edition. Vol. 1, Butherworth-Heinemann, 1999, ISBN 0-7506-3605-X , p. 386.
↑ Ullmann's Encyclopedia of Technical Chemistry. 4th, revised and expanded edition. Volume 16, Verlag Chemie, Weinheim 1978, ISBN 3-527-20016-9 , pp. 419-423.

[Römpp-1] Entry on malononitrile. In: Römpp Online . Georg Thieme Verlag, accessed on July 5, 2016.

[GESTIS-2] ↑ ^a ^b ^c ^d ^e ^f ^g ^h Entry on malonitrile in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .

[CRC90_3_322-3] 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. 3-322.

[CLP_100.003.368-4] Entry on malononitrile 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 .

[merck-5] Data sheet malononitrile (PDF) from Merck , accessed on January 19, 2011.

[CRC90_5_23-6] 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. 5-23.

[evans-7] Evans pK _a table (PDF; 245 kB)

[8] Peter B. Sargeant: Fluorocyclopropanes. I. Preparation and nuclear magnetic resonance spectra. In: Journal of Organic Chemistry. 35 (3), 1970, pp. 678-682.

[9] Process for the preparation of malononitrile

[Grewer-10] T. Grewer, O. Klais: Exothermic decomposition - investigations of the characteristic material properties. (= Humanization of working life. Volume 84). VDI-Verlag, Düsseldorf 1988, ISBN 3-18-400855-X , p. 8.

[11] Bretherick's Handbook of Reactive Chemical Hazards. 6th edition. Vol. 1, Butherworth-Heinemann, 1999, ISBN 0-7506-3605-X , p. 386.

[12] Ullmann's Encyclopedia of Technical Chemistry. 4th, revised and expanded edition. Volume 16, Verlag Chemie, Weinheim 1978, ISBN 3-527-20016-9 , pp. 419-423.