M-Acetophenone Lab Report

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In the primary reduction of m-acetophenone with tin and hydrochloric acid to yield 3-aminoacetophenone, there had to be some experimental precautions taken in order for the reduction to take place. For instance, granular tin was used instead of a single plate of tin because granular particles have more surface area for the reaction to take place on. More surface area means that there is more space for the reaction to occur so it happens more efficiently. Additionally, hydrochloric acid was added slowly to the reaction mixture. This is because the addition of HCl to the reaction mixture of m-acetophenone and tin causes an exothermic reaction that foams and produces hydrogen gas. Hydrogen gas in the presence of heat will explode, so adding the …show more content…

In other words, the addition of concentrated HCl ensures that the reaction occurs. Without a concentrated acid, there would be no reaction at all because NH3 (the amine group) is a weak base. Therefore, a very strong acid is needed to allow the protonation of the oxygen as seen in figure 1 and the subsequent reaction to occur.
The tin used in the experiment eventually dissolved because of the changing oxidation states of the tin. It goes from granular tin to tin chloride and tin chloride is more likely to dissolve. Additionally, other experiments have shown that heat can help dissolve the tin as well8. At this point in the reaction, the hot plate was turned on to increase the desolvation of the tin. In the final stage of the reaction, sodium hydroxide was added which neutralizes the reaction and bonds to hydrogen ions. It causes the SnCl2 to turn into SnOHCl, which is useless as a reducing reagent and thus, shuts the reaction down. Eventually, this SnOHCl is further turned into SnO, which is a solid that is gravity filtered out. This is also why the reaction mixture was heated for a second time because the heat helps facilitate the formation of the tin, hydroxide complex which removes the tin …show more content…

If the N-H bands had not appeared on the product, then the reduction not have taken place. Table 8 shows the NMR results of the same reduction of m-nitroacetophenone to 3-aminoacetophenone. As seen in table 8, the integral under the curve represents the amount of protons, so higher integrals such as 10.37 will have more protons than lower value integrals. Since the reduced compound has an amine group which has more hydrogen atoms, this confirms the IR results that the reduction took

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