Malononitrile

  • Dicyanomethane
  • Malodinitrile
  • Malonitrile
  • Propanedinitrile
  • Methylendinitril
  • Cyanoacetonitril

Colorless crystals

Fixed

1.191 g · cm -3

32 ° C.

220 ° C

1 hPa ( 50 ° C)

Slightly soluble in water ( 133 g · l-1 at 20 ° C)

1.4146 ( 34 ° C)

Risk

  • 25 mg · kg -1 ( LD50, rat, oral)

186.4 kJ / mol

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Malononitrile, also propanedinitrile, is a chemical compound from the class of the nitriles of the formula CH2 ( CN ) 2 Malononitrile is relatively acidic with a pKa of 11 in water. Therefore malononitrile to react in a Knoevenagel condensation, for example for the preparation of 2- chlorobenzylidene - malononitrile.

Production and representation

Malononitrile can be prepared from Chlorcyanoacetylen and ammonia. On an industrial scale malononitrile is produced in the reaction of acetonitrile with cyanogen chloride at about 700 ° C. Other possibilities for the production of go (2 -cyano- N- alkoxy) acetimidoylhalogeniden wherein also temperatures of between 500-1000 ° C are required.

Properties

Malononitrile is a flammable colorless solid which is readily soluble in water. It decomposes at a temperature as 130 ° C, hydrogen cyanide, nitrogen oxides, carbon monoxide and carbon dioxide as possible and an explosion is possible. At lower temperatures, it may be a vigorous polymerization can also proceed explosively on contact with strong bases.

Use

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

CAS registry number PubChem Vapor pressure Dangerous Substances Directive (67/548/EEC) CRC Handbook of Chemistry and Physics Integrated Authority File
542360
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