マロノニトリル

外観

白色/無色～黄色～黄赤色粉末～塊～透明液体

溶解性

水に可溶 (13g/100g水), ほとんどの有機溶剤に易溶。水、エタノール、エーテル、ベンゼンに可溶。クロロホルム、酢酸にかなり可溶。エタノールに溶ける。

解説

マロノニトリル，無色の結晶．融点29～30 ℃，沸点219 ℃，109 ℃(2.66 kPa)，99 ℃(1.47 kPa)．密度1.051 g cm－3．水，エタノールなど有機溶媒に可溶．濃塩酸と処理するとマロン酸になる．メチレン基は活性で，容易にナトリウムやハロゲンと置換する．シアン化ビニリデンの原料になる．

森北出版「化学辞典（第2版）

用途

シアン化ビニリデンの合成原料、有機合成(和光試薬時報Vol.62 No.2,p.23(1994))。

毒性

有毒．LD50 60.8 mg/kg(ラット，経口)．

説明

Malonitrile, also known as Malononitrile, is an aliphatic nitrile that can release cyanide through chemical or biological transformation. It was also used decades ago for treating certain forms of mental illness.

化学的特性

Malononitrile is a white powder or colorless, odorless crystalline substance. It may polymerize violently on prolonged heating at 130°C or at lower temperatures on contact with strong bases.

使用

Malononitrile is an important building block for the syntheses of pharmaceuticals (e.g. triamterene, adenine and methotrexate), thiamin (vitamin B1), pesticides dyestuffs for color photography and synthetic fibers (e.g. vinylidene cyanide). Product Data Sheet

定義

ChEBI: Malononitrile is a dinitrile that is methane substituted by two cyano groups. It is a dinitrile and an aliphatic nitrile.

調製方法

Malononitrile can be synthesized by a continuous method where preheated acetonitrile and cyanogen chloride are introduced into a tube reactor until the reaction mixture reaches a temperature of about 780°C. Another way to prepare malononitrile is by reacting phosphorus pentachloride with cyanoacetamide, or by using phosphorus pentoxide to react with malonamide or cyanoacetamide.
DOI: 10.15227/orgsyn.010.0066

一般的な説明

A white-colored crystalline solid. Denser than water and soluble in water. Toxic by ingestion and may severely irritate skin and eyes. May polymerize violently if exposed to temperatures above 266°F. Used to make other chemicals.

空気と水の反応

Soluble in water.

反応プロフィール

Malononitrile is a white, low-melting powder (m. p. 30.5° C), toxic, combustible. Violent polymerization on contact with strong bases (sodium hydroxide, potassium hydroxide) or when heated above 130° C. When stored at 70-80° C for 2 months, spontaneous explosion (decomposition) occurred [Bretherick, 5th ed., 1995, p. 394].

危険性

Toxic by ingestion and inhalation.

火災危険

When heated to decomposition, Malononitrile emits highly toxic fumes (cyanide). May polymerize violently on prolonged heating. Avoid heat. Hazardous polymerization may occur, at prolonged heating at 266F or contact with strong bases at lower temperatures.

工業用途

Malononitrile is used primarily as an intermediate in the synthesis of drugs and vitamins (thiamine). It has also been employed in the manufacture of photosensitizes, acrylic fibers and dyestuffs and as an oil-soluble polar additive in lubricating oil.
Malononitrile was used formerly in treatment of various forms of mental illness such as alteration of psychic functions and schizophrenic disorders.

安全性プロファイル

Poison by ingestion, skin contact, subcutaneous, intravenous, and intraperitoneal routes. A severe eye irritant. Combustible when exposed to heat or flame. Polymerizes violently when heated to 130°C or on contact with strong base. May spontaneously explode when stored at 70-80°C. To fight fire, use water, fog, spray, foam. When heated to decomposition it emits toxic fumes of NOx and CN-. See also NITRILES.

環境運命予測

When heated to decomposition, nitriles may release cyanide. Malonitrile appears to decompose rapidly in contact with soil and sediment.

代謝

The in vitro metabolsim of malononitrile has been described by Stern et al. In the presence of thiosulphate, brain, liver and kidney slices metabolized malononitrile to thiocyanate. The formation of thiocyanate from malononitrile and thiosulphate was greatest in the presence of liver slices, lowest in brain, and intermediate with kidney slices. The liver enzyme system was saturated at a concentration of 3.3 mM malononitrile and a pH optimum of 7.0. This enzyme system was inhibited by cysteine and glutathione and inactivated by boiling. Stern et al indicated that thiosulphate increased cyanide and thiocyanate formed from malononitrile in tissue slices.

純化方法

Crystallise the nitrile from water, EtOH, *benzene or chloroform. Distil it in a vacuum from, and store over, P2O5. [Bernasconi et al. J Am Chem Soc 107 7692 1985, Gratenhuis J Am Chem Soc 109 8044 1987, Beilstein 2 IV 1892.]

不和合性

Incompatible with strong bases. May polymerize violently on prolonged heating @ 129C, or in contact with strong bases at lower temperatures. Nitriles may polymerize in the presence of metals and some metal compounds. They are incompatible with acids; mixing nitriles with strong oxidizing acids can lead to extremely violent reactions. Nitriles are generally incompatible with other oxidizing agents such as peroxides and epoxides. The combination of bases and nitriles can produce hydrogen cyanide. Nitriles are hydrolyzed in both aqueous acid and base to give carboxylic acids (or salts of carboxylic acids). These reactions generate heat. Peroxides convert nitriles to amides. Nitriles can react vigorously with reducing agents. Acetonitrile and propionitrile are soluble in water, but nitriles higher than propionitrile have low aqueous solubility. They are also insoluble in aqueous acids.