Isopropyl nitrite

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Isopropyl nitrite
Isopropyl nitrite separatory funnel by Doug's Lab.png
Freshly prepared isopropyl nitrite
Names
IUPAC name
2-propyl nitrite
Other names
1-Methylethyl nitrite
Isopropyl alcohol nitrite
Nitrous acid, isopropyl ester
Properties
C3H7NO2
Molar mass 89.09 g/mol
Appearance Straw yellow liquid
Odor Sweet
Density 0.8684 g/cm3
Boiling point 41 °C (106 °F; 314 K)
Insoluble
Solubility Miscible with acetone, diethyl ether, ethanol
Hazards
Safety data sheet Sigma-Aldrich
Flash point -29 °C (-20.2 °F; 244 K)
Lethal dose or concentration (LD, LC):
300 mg/kg (mouse, oral)
3,200 mg/kg (rabbit, oral)
980 mg/kg (rat, oral)[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Isopropyl nitrite is a highly flammable organic ester.

Properties

Chemical

Isopropyl nitrite reacts with hydrazine hydrate and sodium hydroxide to form sodium azide

Physical

Isopropyl nitrite is straw yellow colour and has a sweet, pleasant smell. It is immiscible and less dense than water. Isopropyl nitrite has a very high vapour pressure and a low boiling point, although it will decompose on boiling to produce nitrogen oxides and isopropanol. A low flash point combined with the high vapour pressure means it is very easy to ignite.

Availability

Isopropyl nitrite is better made in a home lab setting. 

Preparation

Concentrated hydrochloric acid is slowly dripped onto sodium nitrite suspended in isopropanol, generating nitrous acid which reacts with the alcohol. The concentration of isopropanol should be less than 100% to ensure the solution does not get too acidic (which will rapidly decompose the ester) and that some of the precipitate byproducts dissolve. Diluted sulfuric acid can also be used but this will result in a larger amount of precipitate due to sodium sulfate's lower solubility compared to sodium chloride.

Every reagent should be as cold as possible to limit decomposition to nitrogen oxides. An ice bath may be needed.

Projects

Handling

Safety

As well as being highly flammable, being an organic nitrite it promotes vascodilation in the body, pushing more blood to the brain. Hence breathing fumes of isopropyl nitrite can have some mild strange side effects that mostly end up in a headache. Proper ventaliation is required when using this compound. 

In case of nitrite poisoning, small dosages of methylene blue are recommended (0.1 ml of 1% solution per kilogram of patient's weight, intravenously). Not to be confused with large dosages, which are toxic in the same way nitrites are, and are used to treat poisoning with blood agents like cyanides, carbon monoxide and hydrogen sulfide (isopropyl nitrite itself can work as an antidote in these cases).

Storage

Storage is best done in a cold place such as a fridge or freezer, but care must be taken to prevent as the vapors travel quickly and can easily find a source of ignition. 

If care is taken to make sure the ester does not contain any acid before storage, it will not quickly decompose and may be stored cold for many months. 

Disposal

Acid hydrolysis of the compound destroys it quickly, with the evolution of nitrogen oxides. It is recommended to either burn it or simply let it evaporate over pouring it down a sink, as its solvent properties may adversely affect a plumbing system. 

References

  1. http://www.chemblink.com/MSDS/MSDSFiles/541-42-4_Clear%20Synth.pdf

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