Acetic anhydride participates in several cyclization reactions.
Tertiary alcohols have been esterified in good yield using acetic anhydride with
Aspirin (Synthesis and Mechanism) | Aspirin | Acetic Acid
Drying and acid removal can be achieved by azeotropic distillation with toluene. acetic anhydride is corrosive and a lachrymator and should be handled in a fume hood.
Both reactions gave the same product after an aqueous workup as shown in eqs 11 and 12. The suggested mechanism involves hydrolysis of phenylacetonitrile to phenylacetamide followed by - and -acylation.
General Mechanism of Anhydride Reactions - …
The clear, yellow solution which is thereby obtained, is if required, allowed to cool off and is then carefully drop for drop mixed with 1.0 ml (d=1.104; MW=78.50 g/mol; about 1.1 g; 14.0 mmol) of acetyl chloride (if any acetyl chloride is spilled it is best to wipe it up with ethanol - with water acetyl chloride reacts rather violently), whereby an intense warming occurs (approximately up to 50 - 60°C).
The reaction proceeds in 81% yield with slow distillation of the acetic acid formed.In 1910, Pummerer reported that sulfoxides react with acetic anhydride to give 2-acetoxy sulfides (eq 21).
Mechanism of the carboxylic acid anhydride synthesis
The classical work-up procedure involving steam distillation was replaced by the hydrolysis of the boron fluoride complex with methanolic sodium hydroxide solution. For example, boron trifluoride gas was bubbled through a mixture of pentan-2-one and propanoic anhydride and the complex was isolated in 89% yield; hydrolysis then gave the diketone in 80% yield (eq 8).
HCl salicylic acid + acetyl chloride + 2-picolin ---> O-acetylsalicylic acid + 2-picolin hydrogen chlorideVoluminous crystallization of acetylsalicylic acid The synthesis was thought of rather spontaneously, still I will at some point try to find a useful reference in the literature.
Acetic anhydride is an esterification agent for use in prepn
The functions are Salicyclic acid, acetic anhydride ..
Cyclic -amino acids rearrange to -methylene lactams upon treatment with acetic anhydride, as shown in eq 11.
How to synthesize aspirin without using acetic anhydride?
Many functionalities are readily dehydrated upon reaction with acetic anhydride, the most notable of which is the
ESTERIFICATION OF SALICYLIC ACID WITH ACETIC ANHYDRIDE MECHANISM ..
The Pummerer rearrangement of 4-phenylsulfinylbutyric acid with acetic anhydride in the presence of leads to
Ferrocene is reacted with acetic anhydride and phosphoric ..
A simple example involves the reaction of benzyldimethylamine with acetic anhydride to give dimethylacetamide and benzylacetate (eq 7).Allylic tertiary amines can be displaced by the reaction of acetic anhydride and sodium acetate. The allylic acetate is the major product, as shown in eq 8.
Mechanism of phthalic anhydride synthesis from pthalic ..
A unique method for selective acylation of secondary amines in the presence of primary amines involves the use of with acetic anhydride and triethylamine. It is believed that the 18-crown-6 complexes primary alkylammonium salts more tightly than the secondary salts, allowing selective acetylation.
Synthesis of aspirin without acetic anhydride - Korbi's …
As shown in eq 43, the tricyclic ether is cleaved by acetic anhydride and pyridine hydrochloride to give the diacetate in 93% yield.Simple dialkyl ethers react with iron(III) chloride and acetic anhydride to produce compounds where both R groups are converted to acetates (eq 44).Cleavage of allylic ethers can occur using acetic anhydride in the presence of iron(III) chloride (eq 45).
Synthesis of aspirin without acetic anhydride
In general, the addition of DMAP increases the rate of acylation by 104 (eq 2).Recently, Vedejs found that a mixture of and acetic anhydride acylates alcohols faster than acetic anhydride with DMAP. However, the combination of acetic anhydride with DMAP and proved superior.
Acetic anhydride, or ethanoic ..
The reaction takes place without isomerization of a double bond, but optically active ethers are cleaved with substantial racemization.Cleavage of aliphatic ethers occurs with the reaction of acetic anhydride, boron trifluoride etherate, and (eq 46).
1) Nucleophilic attack on the carbonyl
The most common method for acetate introduction is the reaction of an alcohol with acetic anhydride in the presence of pyridine. Often, is used as the solvent and reactions proceed nearly quantitatively (eq 1).
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