Organic Chemistry : Ester and Amide 1

From previous group, -COOH, sometimes we have some slightly different organic substance, just replace H in -COOH into others. For example, -COOCH₃ , -COONH₂. These are called Carboxylic Acid Derivatives. Here, we will study only two big ones, Ester and Amide.
- Ester : Replace H in -COOH with some other group such as -COOCH₂CH₃.
- Amide : Replace H in -COOH with N such as -COONHCH₂CH₃.

IUPAC Names

Ester
- Find the longest carbon chain containing the ester group, where the position of the carbonyl carbon must be the first.
- Call the secondary group that replaces the H in -COOH, then call the other side. (the carbon chain side)
- Then, the name is formed by changing the -e of the alkane one to -oate.
- Example :  CH₃CH₂CH₂CH₂-COOCH₂CH₃ = ethylpentanoate

Amide
- Find the longest carbon chain containing the amide group, where the position of the amide  carbon must be the first.
- Call the secondary group (-NRR') that replaces the H in -COOH, then call the other side. (the carbon chain side)
- The position of the Nitrogen atom is denoted as N. (We need to ignore alphabet arrangement for N position because N position must be arranged at the first if exists.)
- Then, the name is formed by changing the -e of the alkane one to -oate.
- Example :  CH₃CH₃CH₂CH(CH₂CH₃)CH₂-COONHCH(CH₃)₂ = N-1-methylethyl-3-ethylhexanamide


Physical Properties

Boiling Points
Amide is the organic substance with the highest boiling point because of dimers (same as carboxylic acid, but stronger.) Ester's boiling point is really low, since the polar around carbonyl group is pretty weak compared to Aldehyde, Ketone, or Carboxylic acid.

Solubility

Carboxylic Acid Derivatives are mostly the same as old carboxylic acids. So small carboxylic acids derivatives are usually soluble.





 Reference : BCC M.5 Chemistry Book.
http://en.wikipedia.org/wiki/Ester
http://en.wikipedia.org/wiki/Amide
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