SYNTHESIS OF p-BROMOANILINE
Introduction:
In this experiment, p-bromoaniline was synthesized in three steps starting from aniline. Since the amino group of aniline is a strong activator of aromatic ring, direct bromination is impractical (equation 1). In order to make a desired product, amino group needed to be protected as the acetamide which also maintained ortho and para position but slowed down the rate of reaction (equation 2). Slow reaction rate would increase the possibility of obtaining the para-position product (equation 3). The acetamide can be hydrolyzed back to the amine (equation 4). This strategy of protection and deprotection is a very important tool in organic chemistry, especially in multi-step synthesis.
Equation 1:
[pic]
Equation 2: [pic]
Equation 3: [pic]
Equation 4: [pic]
Table of Physical data:
|Compound |Molecular |Amount |Density (g/ml) |Moles |Melting point |Boiling point |
| |Weigh (g) | | | |m.p. oC |b.p oC |
|[pic] |93.128 |2.0 ml |1.021 |0.0219 |-6.2 |184 |
|Aniline | | | | | | |
|HCl concentration |36.460 |2.0 ml |0.909 |0.0498 |-114.24 |-85.06 |
|Water |18.015 |50 ml |0.909 |--- |0 |100 |
|[pic] |129.588 | |1.221 | |198 |245 |
|Anilinium chloride | | | | | | |