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Why is sodium acetate used in preparation of acetanilide? What if NaOH is used?
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+ Chemical reactions
+ Sodium acetate
+ Sodium hydroxide
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KENNETH ROTICH
Why is sodium acetate used in preparation of acetanilide? What if NaOH is used?
I assume you are referring to this synthesis, Acetylation of Aniline (Experiment), which first dissolves aniline in hydrochloric acid, then adds acetic anhydride, and finally sodium acetate solution in water.
To figure out what is going on I would ask the question: does aniline react with acetic anhydride on its own? If the answer is yes, then what could be the point of dissolving it in water as the hydrochloride, when it doesn’t react with acetic anhydride in its ionised state?
It’s a mystery until you consider the function of sodium acetate… will it react with anilinium chloride? Yes it will. Would sodium hydroxide react with dissolved acetic anhydride? Yes.
I’ll leave the rest to you to figure out, because TBH I don’t have a definitive answer, just a strong suspicion.
I assume you are referring to this synthesis, Acetylation of Aniline (Experiment), which first dissolves aniline in hydrochloric acid, then adds acetic anhydride, and finally sodium acetate solution in water.
To figure out what is going on I would ask the question: does aniline react with acetic anhydride on its own? If the answer is yes, then what could be the point of dissolving it in water as the hydrochloride, when it doesn’t react with acetic anhydride in its ionised state?
It’s a mystery until you consider the function of sodium acetate… will it react with anilinium chloride? Yes it will. Would sodium hydroxide react with dissolved acetic anhydride? Yes.
I’ll leave the rest to you to figure out, because TBH I don’t have a definitive answer, just a strong suspicion.
Well, it depends on how you do this reaction, and there are quite a few variations. However, the only time I found when sodium acetate was used was when the reaction mixture included Zn and, in this case, it was added during work-up. The reaction conditions were aniline, acetic anhyride, HCl, and Zn dust. After the reaction was complete, the mixture was then quenched with sodium acetate, which would neutralize the HCl and convert it into acetic acid and sodium chloride. The reason for the Zn was to prevent aniline from being oxidized (at least this was the claim). However, in the presence of HCl, the Zn will also react to form Zn(2+) and hydrogen. So, in the final reaction mixture, Zn(2+) is present. If you had NaOH, unless you are very careful not to add too much, you may get Zn(OH)2, which is kind of a gelatinous material when formed this way and may make isolation of the product problematic. Zinc acetate, on the other hand, is very water soluble.
The only alternative is that if you add NaOH, the neutralization is very exothermic (neutralizing both HCl and acetic acid). In principle you may hydrolyzed some of the product back to starting material, but I doubt this. Amides are quite stable and require prolonged heating in the presence of acid or base to cause their hydrolysis (with the exception beta-lactams and a few other unique amides).
Well, it depends on how you do this reaction, and there are quite a few variations. However, the only time I found when sodium acetate was used was when the reaction mixture included Zn and, in this case, it was added during work-up. The reaction conditions were aniline, acetic anhyride, HCl, and Zn dust. After the reaction was complete, the mixture was then quenched with sodium acetate, which would neutralize the HCl and convert it into acetic acid and sodium chloride. The reason for the Zn was to prevent aniline from being oxidized (at least this was the claim). However, in the presence of HCl, the Zn will also react to form Zn(2+) and hydrogen. So, in the final reaction mixture, Zn(2+) is present. If you had NaOH, unless you are very careful not to add too much, you may get Zn(OH)2, which is kind of a gelatinous material when formed this way and may make isolation of the product problematic. Zinc acetate, on the other hand, is very water soluble.
The only alternative is that if you add NaOH, the neutralization is very exothermic (neutralizing both HCl and acetic acid). In principle you may hydrolyzed some of the product back to starting material, but I doubt this. Amides are quite stable and require prolonged heating in the presence of acid or base to cause their hydrolysis (with the exception beta-lactams and a few other unique amides).
I assume you are referring to this synthesis, Acetylation of Aniline (Experiment), which first dissolves aniline in hydrochloric acid, then adds acetic anhydride, and finally sodium acetate solution in water.
To figure out what is going on I would ask the question: does aniline react with acetic anhydride on its own? If the answer is yes, then what could be the point of dissolving it in water as the hydrochloride, when it doesn’t react with acetic anhydride in its ionised state?
It’s a mystery until you consider the function of sodium acetate… will it react with anilinium chloride? Yes it will. Would sodium hydroxide react with dissolved acetic anhydride? Yes.
I’ll leave the rest to you to figure out, because TBH I don’t have a definitive answer, just a strong suspicion.
I assume you are referring to this synthesis, Acetylation of Aniline (Experiment), which first dissolves aniline in hydrochloric acid, then adds acetic anhydride, and finally sodium acetate solution in water.
To figure out what is going on I would ask the question: does aniline react with acetic anhydride on its own? If the answer is yes, then what could be the point of dissolving it in water as the hydrochloride, when it doesn’t react with acetic anhydride in its ionised state?
It’s a mystery until you consider the function of sodium acetate… will it react with anilinium chloride? Yes it will. Would sodium hydroxide react with dissolved acetic anhydride? Yes.
I’ll leave the rest to you to figure out, because TBH I don’t have a definitive answer, just a strong suspicion.
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Well, it depends on how you do this reaction, and there are quite a few variations. However, the only time I found when sodium acetate was used was when the reaction mixture included Zn and, in this case, it was added during work-up. The reaction conditions were aniline, acetic anhyride, HCl, and Zn dust. After the reaction was complete, the mixture was then quenched with sodium acetate, which would neutralize the HCl and convert it into acetic acid and sodium chloride. The reason for the Zn was to prevent aniline from being oxidized (at least this was the claim). However, in the presence of HCl, the Zn will also react to form Zn(2+) and hydrogen. So, in the final reaction mixture, Zn(2+) is present. If you had NaOH, unless you are very careful not to add too much, you may get Zn(OH)2, which is kind of a gelatinous material when formed this way and may make isolation of the product problematic. Zinc acetate, on the other hand, is very water soluble.
The only alternative is that if you add NaOH, the neutralization is very exothermic (neutralizing both HCl and acetic acid). In principle you may hydrolyzed some of the product back to starting material, but I doubt this. Amides are quite stable and require prolonged heating in the presence of acid or base to cause their hydrolysis (with the exception beta-lactams and a few other unique amides).
Well, it depends on how you do this reaction, and there are quite a few variations. However, the only time I found when sodium acetate was used was when the reaction mixture included Zn and, in this case, it was added during work-up. The reaction conditions were aniline, acetic anhyride, HCl, and Zn dust. After the reaction was complete, the mixture was then quenched with sodium acetate, which would neutralize the HCl and convert it into acetic acid and sodium chloride. The reason for the Zn was to prevent aniline from being oxidized (at least this was the claim). However, in the presence of HCl, the Zn will also react to form Zn(2+) and hydrogen. So, in the final reaction mixture, Zn(2+) is present. If you had NaOH, unless you are very careful not to add too much, you may get Zn(OH)2, which is kind of a gelatinous material when formed this way and may make isolation of the product problematic. Zinc acetate, on the other hand, is very water soluble.
The only alternative is that if you add NaOH, the neutralization is very exothermic (neutralizing both HCl and acetic acid). In principle you may hydrolyzed some of the product back to starting material, but I doubt this. Amides are quite stable and require prolonged heating in the presence of acid or base to cause their hydrolysis (with the exception beta-lactams and a few other unique amides).
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