シクロプロパン

反応性

シクロアルカンの一つ。トリメチレンともいう。無色の可燃性気体。酸素と爆鳴気をつくる。合成は1,3-ジクロロプロパンと亜鉛のウルツ反応によるか、エチレンへのカルベン付加反応（シモンズ‐スミス反応）による（図）。シクロプロパンは炭素結合角のひずみが大きく、そのため3員環を構成している炭素‐炭素結合（C-C）は折れ曲がった結合（バナナ結合）である。開環のとき、ひずみのエネルギーを放出するので、他のシクロアルカンよりはるかに反応性に富んでいる。ニッケル触媒上、120℃で水素化され、プロパンを与える。ルイス酸触媒下では臭素と反応して1,3-ジブロモプロパンを、また、水が付加して1-プロパノールを生成する。［向井利夫］

用途

化学式 C3H6 。シクロアルカンの一種。ジブロムプロパンから合成される。特異臭のある無色で引火性の気体。沸点－34℃。分子構造がきわめてひずんでいるため，化学的に活性で，水素2原子を付加して n－ プロパンになる。シクロプロパンは，そのほか炭素-炭素二重結合に似た反応を起す。ただし二重結合よりも活性ではない。空気との混合物は引火爆発する。吸入麻酔薬として使われる。除虫菊の有効成分ピレスリンはその分子構造中にシクロプロパン環をもっている。

解説

C3H6(42.08)．1,3-ジブロモプロパンを金属ナトリウムと処理すると得られる．無色の気体．融点－126.6 ℃，沸点－34 ℃．燃焼熱2091 kJ mol－1．ニッケル上で120 ℃ で還元するとプロパンになる．引火性，爆発性があり，また吸入麻酔薬に使われる．森北出版「化学辞典（第2版）

用途

有機合成原料、麻酔薬

効能

吸入麻酔薬

説明

Cyclopropane (molecular formula: C3H6) is a kind of cycloalkane molecule. Cyclopropane and propene are isomers of each other. It can be used as a kind of anaesthetic. However, due to its side effect of causing a sudden decrease in blood pressure and potentially causing cardiac dysrhythmia, it has not been available for clinical use since mid-1980 as more. Its mechanism of action is through acting as the NMDA receptor antagonist as well as inhibiting the AMPA receptor, inhibiting the nicotine acetylcholine receptor, and activates certain K2P channels.

化学的特性

Cyclopropane is a colourless gas, C3H6, b.p. –34.5°C, whose moleculescontain a triangular ring of carbonatoms. It is made by treating 1,3-dibromopropanewith zinc metal, andis used as a general anaesthetic.

使用

Cyclopropane was initially investigated because it was thought to be the toxic element in ethylene. Instead, it turned out to be an excellent anesthetic with very rapid onset and recovery while maintaining stable hemodynamics. Its use was ultimately limited because it was highly explosive. Cyclopropane is a sweet-smelling, flammable gas that has little or no laboratory, commercial, or industrial use.

調製方法

Cyclopropane is prepared in reagent grade by the reduction of 1,2-dibromocyclopropane with zinc and alcohol.

定義

ChEBI: Cyclopropane is a cycloalkane composed of three carbon atoms to form a ring. It has a role as an inhalation anaesthetic. It is a cycloalkane and a member of cyclopropanes.

一般的な説明

Cyclopropane is a colorless gas with a petroleum-like odor. It is shipped as a liquid at 4-6 atms. It is easily ignited. The vapors are heavier than air. Contact with the liquid may cause frostbite. It can asphyxiate by the displacement of air and has a narcotic effect in high concentration (formerly used as an anesthetic gas). Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket.

空気と水の反応

Highly flammable. Insoluble in water.

反応プロフィール

CYCLOPROPANE is incompatible with strong oxidizing agents such as nitric acid. Boiling of the liquid and charring may occur followed by ignition of remaining material and other nearby combustibles. Adsorbed readily by concentrated sulfuric acid [Merck]. In other settings, mostly unreactive. Not affected by aqueous solutions of acids, alkalis, most oxidizing agents, and most reducing agents. When heated sufficiently or when ignited in the presence of air, oxygen or strong oxidizing agents, burns exothermically to produce carbon dioxide and water. Mixtures with oxygen or air may explode [Merck]. Contact of the cold liquefied gas with water may result in vigorous or violent boiling and extremely rapid vaporization due to the large temperature differences involved. If the water is hot, a liquid "superheat" explosion may occur. Pressures may build to dangerous levels if the liquid contacts water in a closed container, [Handling Chemicals Safely, 1980. p. 250].

健康ハザード

Inhalation causes some analgesia, anesthesia, pupil dilation, shallow depth of respirations, decreasing muscle tone. Contact with liquid may cause frostbite.

火災危険

EXTREMELY FLAMMABLE. Will be easily ignited by heat, sparks or flames. Will form explosive mixtures with air. Vapors from liquefied gas are initially heavier than air and spread along ground. CAUTION: Hydrogen (UN1049), Deuterium (UN1957), Hydrogen, refrigerated liquid (UN1966) and Methane (UN1971) are lighter than air and will rise. Hydrogen and Deuterium fires are difficult to detect since they burn with an invisible flame. Use an alternate method of detection (thermal camera, broom handle, etc.) Vapors may travel to source of ignition and flash back. Cylinders exposed to fire may vent and release flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket.

安全性プロファイル

Mutation data reported. Questionable carcinogen. High concentrations are narcotic. Human reproductive effects. Very dangerous fire hazard when exposed to heat or flame; can react with oxidizing materials. Explosion Hazard: Moderate in the form of vapor when exposed to heat or flame. To fight fire, stop flow of gas, then use CO2, dry chemical, or water spray. When heated to decomposition it emits acrid smoke and fumes.

職業ばく露

Cyclopropane is used as an anesthetic and used to make other chemicals.

輸送方法

UN1027 Cyclopropane, Hazard Class: 2.1; Labels: 2.1-Flammable gas. Cylinders must be transported in a secure upright position, in a well-ventilated truck. Protect cylinder and labels from physical damage. The owner of the compressed gas cylinder is the only entity allowed by federal law (49CFR) to transport and refill them. It is a violation of transportation regulations to refill compressed gas cylinders without the express written per- mission of the owner.

純化方法

Wash cyclopropane with a solution of HgSO4 and dry it with CaCl2, then Mg(ClO4)2. It is an anaesthetic FLAMMABLE gas and is packaged in steel cylinders. [Rifi Org Synth Coll 52 22 1972, Simmons & Smith J Am Chem Soc 80 5323 1958, Beilstein 5 H 15.]

不和合性

May form explosive mixture with air. Heat, flame, or contact with oxidizers can cause fire and explosion hazard. May accumulate static electrical charges, and may cause ignition of its vapors. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materi- als, strong bases, strong acids, oxoacids, epoxides.

廃棄物の処理

Return refillable compressed gas cylinders to supplier.

参考文献

https://en.wikipedia.org/wiki/Cyclopropane