Tuesday, February 5, 2008

Carboxylic acids - introduction

1. Carboxylic acids are the compound containing carboxyl group in their molecules.

-C with a double bond with oxygen and single bond with OH

2. These acides can be aliphatic or aromatic.

aliphatic acids:

Formic acid HCOOH
Acetic acid CH-3COOH
Isobutyric acid (Branched)

aromatic acids

Bezoic acid : H in benzene substituted by COOH

m-Nitrobenzoic acid: One more H substituted by NO-2

o-Toluic acid (o refers to ortho) Benzoic acid with one more H substituted by CH-3

Both aliphatic and aromatic carboxylic acids are further classified as mono, di, tricarboxylic acids depending upon the number of carboxylic groups present in their molecules.

Some dicarboxylic acids

Oxalic acid COOOH-COOH
Malonic acd CH2(COOH)2
Succinic acid (CH2COOH)2
Phthalic acid is an aromatic dicarboxylic acid Ar(COOH)2. 2nd COOH is in ortho position
Phthalic acid come in the amines, as primary amines are prepared from Phthalimide using Gabriel's phthalimide synthesis.
Isophthalic acid (2nd COOH in meta position)
Terephtalic acid (2nd COOH in para position)


According to IUPAC system, the name of the monocarboxylic acid is derived by changing the final 'e' from the name of the corresponding hydrocarbon with 'oic' and adding the word acid.

Formic acid - Methanoic acid
Acetic acid - Ethanoic acid
n-Butyric acid - Butanoic acid
Isobutyric acid - 2-Mehtylpropanoic acid

Dicarboxylic acids

Oxalic acid - Ethanedioic acid
Malonic acid - Propanedioic acid

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