シアナミド

種類

シアナミドとカルボジイミドは互換異性体の関係にあります。カルボジイミドは仮想化合物であり、単離することはできません。塩基性溶液中では、シアナミドとカルボジイミドの反応により二量体のジシアンジアミドを生成します。

性質

化学式はCH₂N₂で表され、分子量は42.04です。CAS番号は420-04-2で登録されています。シアナミドは融点45°C、沸点は260°Cで、密度1.282g/ml (20℃) 、常温で無色の結晶性固体です。

斜方晶や針状晶、板状結晶など、様々な結晶形を有します。141°Cに引火点を持ち、空気中の水分を吸収して溶けだす潮解性があります。水やアルコール、エーテルなど極性溶媒によく溶け、やなどの非極性溶媒にはあまり溶けません。

酸解離定数 (pKa) は10.3 (25 °C) です。酸解離定数とは、酸の強さを定量的に表すための指標の1つです。pKaが小さいほど強い酸であることを示します。

溶解性

水、エタノール及びアセトンに溶けやすい。

解説

CH2N2(42.04)．H2N-C≡N．シアンのアミド化物で、シアンアミドともいう。アンモニアとクロロシアンCNClとの反応、カルシウムシアナミド（石灰窒素の主成分）CaCN2と酢酸との反応、チオ尿素と酸化水銀(Ⅱ)との反応などによって得られる。互変異性体のカルボジイミドHN=C=NHは，仮想化合物であり単離できない．カルシウムシアナミドに硫酸を作用させるか，塩化シアンとアンモニアからつくる．無色の潮解性針状晶．融点45～46 ℃．d₄²⁰"1.282．水，エタノール，エーテルに易溶，二硫化炭素，クロロホルムに難溶．熱または弱アルカリ性では二分子重合してジシアンジアミドとなり，水酸化ナトリウム水溶液ではNaHCN2なる化合物を生じる．Na，K，Ca，Ba，Mg，Ag，Hg，Cu，Pbなどと安定な塩をつくる．シアナミドは強塩基または強酸中で加水分解されて尿素になる．硫化水素と弱塩基性で反応させればチオ尿素に，アンモニウム塩とではグアニジン塩になる．CNNH2 ＋ NH4NO3 → H2NC(=NH)NH2HNO3Ca塩は肥料として使われる．森北出版「化学辞典（第2版）

製造法

カルシウムシアナミドに水を作用させ、二酸化炭素を吹き込むとシアナミド水溶液が得られます。この水溶液に対し、を用いて中和し、その後濃縮することにより、針状結晶のシアナミドが生成します。

また、カルシウムシアナミドと酢酸の反応や塩化シアンとの反応、と酸化水銀 (II) の反応などによっても合成可能です。水などの溶媒から、再結晶にて精製できます。

用途

有機合成原料、チオ尿素原料、農薬(植物成長調整剤)、医薬

効能

抗酒癖薬, アルデヒドデヒドロゲナーゼ阻害薬

商品名

シアナマイド (田辺三菱製薬)

使用上の注意

潮解性あり

説明

Cyanamide and its salts are used on various occasions, such as in chemistry, in anti-rust solutions or in drugs for treating alcoholism (Come).

化学的特性

Cyanamide is a combustible crystalline solid, but it is usually found as a 25% liquid solution.

使用

In Europe, cyanamide is used as a fertilizer, weed killer, and defoliant. In North America, these applications have been practically discontinued. It is also used to produce cationic starch and calcium cyanide, dicyandiamide, and melamine. New uses include intermediates for pesticides; detergents; medicines such as antihistamines, hypertension, sedatives, and contraceptives; photography industry; additive for fuels and lubricants; paper preservative; and cement additive. Dormex is a common rest-breaking agent applied in spring to stimulate uniform opening of buds.
Cyanamide has been tested as an effective and welltolerated pharmacological adjunct to treat alcohol-dependent patients. It is a potent aldehyde dehydrogenase inhibitor, and alters cholinergic function in the frontal cortex and hippocampus of rats exposed to ethanol.

調製方法

The basic process for the manufacture of cyanamide comprises four steps. The first three steps produce calcium cyanamide: lime is made from high grade limestone; (2) calcium carbide is manufactured from lime and coal or coke; calcium cyanamide is produced by passing gaseous nitrogen through a bed of calcium carbide with 1% calcium fluorspar, which is heated to 1000–1100°C to start the reaction—the heat source is then removed and the reaction continues because of its strong exothermic character; and cyanamide is manufactured from calcium cyanamide by continuous carbonation in an aqueous medium.

定義

cyanamide: 1. An inorganic saltcontaining the ion CN₂^{2-. See calciumcyanamide. 2. A colourless crystallinesolid, H₂NCN, made by the actionof carbon dioxide on hotsodamide. It is a weakly acidic compound(the parent acid of cyanamidesalts) that is soluble in water andethanol. It is hydrolysed to urea inacidic solutions.}

反応性

Cyanamide reacts (1) as a base with strong acids forming salts, (2) as an acid forming metallic salts, such as calcium cyanamide CaCN2. Cyanamide is formed (1) by reaction of cyanogen chloride CN·Cl plus ammonia (ammonium chloride also formed), (2) by reaction of thiourea plus lead hydroxide (lead sulfide also formed).

一般的な説明

Colorless deliquescent crystals. Mp: 45°C; bp: 260°C. Density: 1.282 g cm-3. Quite soluble in water (77 g / 100 g solution at 15°C). Soluble in butanol, methyl ethyl ketone, ethyl acetate, alcohols, phenols, amines, ethers. Note: The term "Cyanamide" is also used to refer to the important compound calcium Cyanamide, which is a different chemical.

反応プロフィール

Cyanamide is the amide of cyanic acid. Non-flammable but combustible (flash point: 140°C). Decomposes on warming above 49°C. Emits toxic fumes of CN- and NOx when heated to decomposition or on contact with acids or acid fumes (Hazardous Chemicals Desk Reference, p. 353 (1987)). Contact with moisture, acids or bases may cause a violent reaction at temperatures above about 40°C. Dry solid may polymerize at temperatures above 122°C. Rapid or explosive polymerization may occur during the evaporation of aqueous solutions. Reacts explosively with strong oxidizing agents and strong reducing agents. Attacks various metals (International Chemical Safety Card).

危険性

Strong irritant to skin and mucous membranes; avoid inhalation or ingestion.

健康ハザード

Cyanamide is an irritant of the eyes, mucous membranes, and skin; it is an inhibitor of aldehyde dehydrogenase and can cause an “antabuse” effect with ethanol ingestion.
Cyanamide is severely irritating and caustic to the eyes, skin, and respiratory tract.

使用用途

シアナミドの塩は、農業分野で農薬や肥料として用いられます。殺虫・殺菌・除草作用を持つことに加え、散布されると徐々に、最終的にアンモニア態窒素や硝酸態窒素へ変換され、農作物の肥料成分になります。

农业用途

Herbicide, Plant growth regulator: A U.S. EPA restricted Use Pesticide (RUP). Not currently approved for use in EU countries (re-submitted). Used primarily as a plant growth regulator. Cyanamide may be melted to give a dimer, dicyandiamide or cyanoguanidine. At higher temperatures it gives the trimer, melamine, a raw material for melamine-formaldehyde resins.

製品名

DORMEX®; SKW 83010®

接触アレルゲン

Cyanamide and its salts are used in various occasions such as in chemistry, in antirust solutions, or in a drug (Come?) for treating alcoholism (inhibition of alcohol deshydrogenase).

安全性プロファイル

Poison by ingestion, inhalation, and intraperitoneal routes. Moderately toxic by skin contact. Experimental reproductive effects. Combustible when exposed to heat or flame. To fight fire, use CO2, dry chemical. Thermally unstable. Contact with moisture (water), acids, or alkalies may cause a violent reaction above 40'. Concentrated aqueous solutions may undergo explosive polymerization. Mixture with 1,2 phenylenediamine salts may cause explosive polymerization. When heated to decomposition or on contact with acid or acid fumes, it emits toxic fumes of CNand NOx. See also CYANIDE and AMIDES.

職業ばく露

Cyanamide may be melted to give a dimer, dicyandiamide or cyanoguanidine. At higher tem- peratures it gives the trimer, melamine; a raw material for melamine-form aldehyde resins.

概要

シアナミド (英: Cyanamide) とは、シアンのアミド化物です。

IUPAC名はシアナミド、別名として、シアンアミドやアミドシアノゲン (英: Amidocyanogen) 、シアノゲンアミド (英: Cyanogenamide) 、カルバモニトリル (英: Carbamonitrile) 、カルバミン酸ニトリル (英: Carbamic nitrile) などとも呼ばれます。

輸送方法

UN3276 Nitriles, liquid, toxic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required, Potential Inhalation Hazard (Special Provision 5).

純化方法

Purify it by placing ca 15g in a Soxhlet thimble and extracting exhaustively (2-3hours) with two successive portions of Et2O (400mL, saturated with H2O by shaking before use) containing two drops of 1N acetic acid. Two successive portions of Et2O are used so that the NH2CN is not heated for too long. Each extract is dried over Na2SO4 (30g), then combined and evaporated under reduced pressure. The NH2CN may be stored unchanged at 0o in Et2O solution in the presence of a trace of AcOH. Extracts from several runs may be combined and evaporated together. The residue from evaporation of an Et2O solution is a colourless viscous oil which sets to a solid and can be recrystallised from a mixture of 2 parts of *C6H6 and 1 part of Et2O. Concentrating an aqueous solution of NH2CN at high temperatures causes EXPLOSIVE polymerisation. [Kurzer & Lawson Org Synth Coll Vol IV 645 1963, Pinck & Salissbury Inorg Synth III 39 1950, Soloway & Lipschitz J Org Chem 23 613 1958.] Hygroscopic.[Beilstein 3 IV 145.]

不和合性

Cyanamide may polymerize at tempera- tures above 122℃ , or on evaporation of aqueous solutions. Reacts with acids, strong oxidants, strong reducing agents such as hydrides and water, causing explosion and toxic hazard. Attacks various metals. Decomposes when heated above 49℃ C, on contact with acids, bases, 1,2-phenylene diamine salts; and moisture; producing toxic fumes includ- ing nitrogen oxides and cyanides. 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 reac- tions. Nitriles are generally incompatible with other oxi- dizing 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 .

廃棄物の処理

Add excess alkaline calcium hypochlorite with agitation. Flush to sewer after 24 hours. Cyanamide can also be destroyed in an incinerator equipped with afterburner and scrubber.