Full Answer
What is the use of NaN3 in synthesis?
Chemical Formula: NaN3 Sodium azide is versatile reagent for a variety of synthetic transformations. A common use is for the formation of azides via substitution or SNAr reactions. These azides are often then reduced to give the corresponding amine products.
How do you mix NaN3 and SM solution?
To a solution of the SM (0.3 g, 0.97 mmol) in DMF(10 mL) was added NaN3 (127 mg, 1.94 mmol) at 0 C. The reaction mixture was stirred at RT for 16 h.
Is Nn3 3 a linear anion?
N − 3 is a linear anion that is isoelectronic with CO2, NCO−, N2O, NO + Also, is azide a good leaving group? The azide function is a good leaving group similar to the N-hydroxysuccinimide group of NHS ester compounds. A coupling reaction with an amine group occurs by attack of the nucleophile at the electron-deficient carbonyl group (Reaction 3.3).
How much NaN3 do you add to DMF?
To a stirring solution of the SM (100 mg, 0.15 mmol) in DMF(5 mL) was added NaN3 (50 mg, 0.7 mmol) and the reaction mixture was stirred at RT for 3 h. The mixture was . . .
What is NaN3 used for in organic chemistry?
In the laboratory, it is used in organic synthesis to introduce the azide functional group by displacement of halides.
What is the function of NaN3?
Sodium azide is the sodium salt of hydrogen azide (hydrazoic acid). It has a role as a mutagen, an antibacterial agent, an explosive and a mitochondrial respiratory-chain inhibitor.
What does NaN3 do to an alkyl halide?
Description: Alkyl halides (or tosylates) will react with azide ions (such as NaN3 or KN3) in an SN2 reaction to give alkyl azides.
Is azide a good nucleophile?
The Azide Ion Is A Great Nucleophile In SN2 Reactions The azide ion is the conjugate base of hydrazoic acid, HN3. Despite being only weakly basic (the pKa of HN3 is only 4.6) N3 is an extremely good nucleophile – according to one measure, more nucleophilic than any amine (see post: Nucleophilicity of amines).
Is NaN3 acidic or basic?
NaNO3 is neither an acid nor a base. It is made from the neutralization reaction of the strong acid, namely Nitric acid (HNO3) with a strong base, namely Sodium hydroxide (NaOH). The pH value of the aqueous solution of NaNO3 is 7.
How does azide affect cellular respiration?
Similar to cyanide, sodium azide and hydrozoic acid also interfere with cellular respiration and aerobic metabolism, preventing the cells from using oxygen. The central nervous system and the cardiovascular system are most sensitive to acute sodium azide poisoning.
Why is azide added to reaction mixture?
Azide is added to suppress the interference from nitrite present that would react with the iodide.
Is azide a good leaving group?
However, an unmodified azido group is not considered to be a good leaving group. Consequently, we postulate the formation of an intermediate showing electrophilic nature at the position bearing the azide.
Is azide a nucleophile or electrophile?
nucleophileThe azide anion behaves as a nucleophile; it undergoes nucleophilic substitution for both aliphatic and aromatic systems. It reacts with epoxides, causing a ring-opening; it undergoes Michael-like conjugate addition to 1,4-unsaturated carbonyl compounds.
What does azide mean in chemistry?
azide, any of a class of chemical compounds containing three nitrogen atoms as a group, represented as (-N3).
Is azide electron donating or withdrawing?
While amines are strong electron-donating substituents, azides are weakly electron-withdrawing.
Are azides acid sensitive?
Heavy metal azide salts tend to be highly heatand shock-sensitive explosives. Avoid water and strong acids which can lead to the formation of hydrazoic acid, which is highly toxic, volatile, and explosive.
What is nucleophilic substitution?
Nucleophilic substitution is the reaction of an electron pair donor (the nucleophile, Nu) with an electron pair acceptor (the electrophile). An sp 3 -hybridized electrophile must have a leaving group (X) in order for the reaction to take place.
What is the role of polar protic solvents in reducing reactivity?
An additional factor that plays a role is the character of the solvent. Increasing stabilization of the nucleophile by the solvent results in decreasing reactivity. Thus, polar protic solvents will stabilize the chloride and bromide ions through the formation of hydrogen bonds to these smaller anions.
Which anions are strong acids?
Triflate, tosylate and mesylate are the anions of strong acids. The weak conjugate bases are poor nucleophiles. Nucleophilicity increases in parallel with the base strength. Thus, amines, alcohols and alkoxides are very good nucleophiles.
Which solvent is more likely to follow the S N 1 pathway?
The more highly substituted is the incipient carbenium ion, the more probable that the reaction will follow an S N 1 pathway.
Which group stabilizes an incipient negative charge?
Very good leaving groups, such as triflate, tosylate and mesylate, stabilize an incipient negative charge. The delocalization of this charge is reflected in the fact that these ions are not considered to be nucleophilic.
Is base strength necessary for nucleophiles?
Base strength is a rough measure of how reactive the nonbonding electron pair is; thus, it is not necessary for a nucleophile to be anionic. Under substitution conditions, amines proceed all the way to form quaternary salts, which makes it difficult to control the extent of the reaction.
Overview
Applications
Older airbag formulations contained mixtures of oxidizers and sodium azide and other agents including ignitors and accelerants. An electronic controller detonates this mixture during an automobile crash:
2 NaN3 → 2 Na + 3 N2
The same reaction occurs upon heating the salt to approximately 300 °C. The sodium that is for…
Structure
Sodium azide is an ionic solid. Two crystalline forms are known, rhombohedral and hexagonal. Both adopt layered structures. The azide anion is very similar in each form, being centrosymmetric with N–N distances of 1.18 Å. The Na ion has an octahedral geometry. Each azide is linked to six Na centers, with three Na-N bonds to each terminal nitrogen center.
Preparation
The common synthesis method is the "Wislicenus process", which proceeds in two steps in liquid ammonia. In the first step, ammonia is converted to sodium amide by metallic sodium:
2 Na + 2 NH3 → 2 NaNH2 + H2
It is a redox reaction in which metallic sodium gives an electron to a proton of ammonia which is reduced in hydrogen gas. Sodium easily dissolves in liquid ammonia to produce hydrated electrons responsible …
Chemical reactions
Treatment of sodium azide with strong acids gives hydrazoic acid, which is also extremely toxic:
H + N−3 → HN3
Aqueous solutions contain minute amounts of hydrogen azide, the formation of which is described by the following equilibrium:
N−3 + H2O ⇌ HN3 + OH (K = 10 )
Safety considerations
Sodium azide has caused deaths for decades, and even minute amounts can cause symptoms. The toxicity of this compound is comparable to that of soluble alkali cyanides, although no toxicity has been reported from spent airbags.
It produces extrapyramidal symptoms with necrosis of the cerebral cortex, cerebellum, and basal ganglia. Toxicity may also include hypotension, blindness and hepatic necrosis. Sodium azide incr…
External links
• International Chemical Safety Card 0950.
• NIOSH Pocket Guide to Chemical Hazards.
• Straight Dope on Sodium Azide