Malononitrile

Malononitrile
Ball-and-stick model	Space-filling model
Names
	IUPAC name Malononitrile
	Preferred IUPAC name Propanedinitrile
	Other names Malonodinitrile, Cyanoacetonitrile, Dicyanomethane, Malonic dinitrile
Identifiers
CAS Number	109-77-3 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	773697
ChEBI	CHEBI:33186 ;
ChemSpider	13884495 ;
ECHA InfoCard	100.003.368
EC Number	203-703-2;
Gmelin Reference	1303
MeSH	dicyanmethane
PubChem CID	8010;
RTECS number	OO3150000;
UNII	EBL1KKS93J ;
UN number	2647
CompTox Dashboard (EPA)	DTXSID6021907 ;
	InChI InChI=1S/C3H2N2/c4-2-1-3-5/h1H2 Key: CUONGYYJJVDODC-UHFFFAOYSA-N ;
	SMILES N#CCC#N;
Properties
Chemical formula	CH2(CN)2
Molar mass	66.063 g·mol−1
Appearance	Colourless or white solid
Density	1.049 g cm−3
Melting point	32 °C; 89 °F; 305 K
Boiling point	220.1 °C; 428.1 °F; 493.2 K
Solubility in water	13% (20 °C)[clarification needed]
Thermochemistry
Heat capacity (C)	110.29 J K−1 mol−1
Std molar; entropy (S⦵298)	130.96 J K−1 mol−1
Std enthalpy of; formation (ΔfH⦵298)	187.7 to 188.1 kJ mol−1
Std enthalpy of; combustion (ΔcH⦵298)	−1,654.0 to −1,654.4 kJ mol−1
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H301, H311, H331, H410
Precautionary statements	P261, P273, P280, P301+P310, P311
Flash point	86 °C (187 °F; 359 K)
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	19 mg kg−1 (oral, mouse); 350 mg kg−1 (dermal, rat);
	NIOSH (US health exposure limits):
PEL (Permissible)	none
REL (Recommended)	TWA 3 ppm (8 mg/m3)
IDLH (Immediate danger)	N.D.
Related compounds
Related alkanenitriles	Acetonitrile; Aminoacetonitrile; Glycolonitrile; Cyanogen; Propanenitrile; Aminopropionitrile; Pivalonitrile; Acetone cyanohydrin; Butyronitrile; Succinonitrile; Tetramethylsuccinonitrile;
Related compounds	Malonic acid
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Malononitrile is an organic compound nitrile with the formula CH₂(CN)₂. It is a colorless or white solid, although aged samples appear yellow or even brown. It is a widely used building block in organic synthesis.

Preparation and reactions

It can be prepared by dehydration of cyanoacetamide.^[3] This method is mainly practiced in China where environmental rules are lax. Most commonly malononitrile is produced by the gas-phase reaction of acetonitrile and cyanogen chloride:^[4]

NCCl + CH₃CN → NCCH₂CN + HCl

About 20,000,000 kg are produced annually (2007). Important outlets include the synthesis of thiamine, the drug triamterene and minoxidil, and the dyes disperse Yellow 90 and disperse Blue 354.^[4]

Malononitrile is relatively acidic, with a pK_a of 11 in water.^[5] This allows it to be used in the Knoevenagel condensation, for example in the preparation of CS gas:

Despite its relative obscurity, Malononitrile is very useful in several reactions, the prime example being a suitable starting reagent for the Gewald reaction, where the nitrile condenses with a ketone or aldehyde in the presence of elemental sulfur and a base to produce a 2-aminothiophene.^[6]

Interstellar occurrence

Due to its permanent dipole moment (i.e., 3.735 ± 0.017 D)^[7], malononitrile was detected in spectral emissions coming from interstellar cloud TMC-1 through the QUIJOTE line survey conducted with the Yebes 40 m radio telescope.^[8]^[9]

References

^ ^a ^b ^c ^d ^e ^f NIOSH Pocket Guide to Chemical Hazards. "#0378". National Institute for Occupational Safety and Health (NIOSH).
^ ^a ^b International Union of Pure and Applied Chemistry (2014). Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013. The Royal Society of Chemistry. p. 902. doi:10.1039/9781849733069. ISBN 978-0-85404-182-4.
^ Surrey, Alexander (1945). "Malononitrile". Organic Syntheses. 25: 63–64. doi:10.15227/orgsyn.025.0063.
^ ^a ^b Strittmatter, Harald; Hildbrand, Stefan; Pollak, Peter (2007). "Malonic Acid and Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a16_063.pub2. ISBN 978-3527306732.
^ Evans pK_a table
^ Sabnis, R. W.; Rangnekar, D. W.; Sonawane, N. D. (1999). "2-Aminothiophenes By The Gewald Reaction". Journal of Heterocyclic Chemistry. 36 (2): 333–345. doi:10.1002/jhet.5570360203. Retrieved 2007-07-18.
^ Hirota, Eizi; Morino, Yonezo (1960-02-01). "Microwave Spectrum of Malononitrile, CH2(CN)2. I. The Molecular Structure in the Ground Vibrational State". Bulletin of the Chemical Society of Japan. 33 (2): 158–162. doi:10.1246/bcsj.33.158. ISSN 0009-2673.
^ Agúndez, M.; Bermúdez, C.; Cabezas, C.; Molpeceres, G.; Endo, Y.; Marcelino, N.; Tercero, B.; Guillemin, J.-C.; de Vicente, P.; Cernicharo, J. (August 2, 2024). "The rich interstellar reservoir of dinitriles: Detection of malononitrile and maleonitrile in TMC-1". Astronomy & Astrophysics. 688: L31. doi:10.1051/0004-6361/202451525. ISSN 0004-6361. Retrieved January 7, 2025.
^ published, Victoria Corless (2024-11-12). "Scientists found 'nitriles' in an interstellar cloud — here's why that could be huge". Space.com. Retrieved 2025-01-07.

External links

[PGCH-1] ^ ^a ^b ^c ^d ^e ^f NIOSH Pocket Guide to Chemical Hazards. "#0378". National Institute for Occupational Safety and Health (NIOSH).

[IUPAC2014-2] International Union of Pure and Applied Chemistry (2014). Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013. The Royal Society of Chemistry. p. 902. doi:10.1039/9781849733069. ISBN 978-0-85404-182-4.

[3] Surrey, Alexander (1945). "Malononitrile". Organic Syntheses. 25: 63–64. doi:10.15227/orgsyn.025.0063.

[UllMal-4] Strittmatter, Harald; Hildbrand, Stefan; Pollak, Peter (2007). "Malonic Acid and Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a16_063.pub2. ISBN 978-3527306732.

[5] Evans pK_a table

[Sabnis1999-6] Sabnis, R. W.; Rangnekar, D. W.; Sonawane, N. D. (1999). "2-Aminothiophenes By The Gewald Reaction". Journal of Heterocyclic Chemistry. 36 (2): 333–345. doi:10.1002/jhet.5570360203. Retrieved 2007-07-18.

[7] Hirota, Eizi; Morino, Yonezo (1960-02-01). "Microwave Spectrum of Malononitrile, CH2(CN)2. I. The Molecular Structure in the Ground Vibrational State". Bulletin of the Chemical Society of Japan. 33 (2): 158–162. doi:10.1246/bcsj.33.158. ISSN 0009-2673.

[8] Agúndez, M.; Bermúdez, C.; Cabezas, C.; Molpeceres, G.; Endo, Y.; Marcelino, N.; Tercero, B.; Guillemin, J.-C.; de Vicente, P.; Cernicharo, J. (August 2, 2024). "The rich interstellar reservoir of dinitriles: Detection of malononitrile and maleonitrile in TMC-1". Astronomy & Astrophysics. 688: L31. doi:10.1051/0004-6361/202451525. ISSN 0004-6361. Retrieved January 7, 2025.

[9] ublished, Victoria Corless (2024-11-12). "Scientists found 'nitriles' in an interstellar cloud — here's why that could be huge". Space.com. Retrieved 2025-01-07.

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