In this article, we will discuss about the versatile synthesis and reactions of carboxylic acids. Carboxylic acids are the organic compounds with general formula R-C=OOH. These are of two types: Monocarboxylic acids and dicarboxylic acids. We will also discuss the mechanisms of these reactions. These reactions provide various pharmaceutical, industrial and organic products. We will also provide references to understand the concept deeply.
INTRODUCTION OF SYNTHESIS AND REACTIONS OF CARBOXYLIC ACIDS:
Carboxylic acids are a versatile class of organic compounds that play a crucial role in various chemical reactions and biological processes. They are characterized by the presence of a carboxyl group (-COOH), which consists of a carbonyl group (C=O) and a hydroxyl group (-OH) attached to the same carbon atom. This article aims to delve into the preparations and reactions of carboxylic acids, highlighting the underlying mechanisms and providing references for further exploration.
SYNTHESIS AND REACTIONS OF CARBOXYLIC ACIDS:
1. SYNTHESIS OF CARBOXYLIC ACIDS:
a) OXIDATION OF PRIMARY ALCOHOLS:
One of the most common methods for preparing carboxylic acids involves the oxidation of primary alcohols. This reaction can achieve using various oxidizing agents such as potassium permanganate (KMnO4) or chromium trioxide (CrO3). The mechanism involves the conversion of the alcohol to an aldehyde, followed by further oxidation to the carboxylic acid.
b) OXIDATION OF ALDEHYDES:
Aldehydes can also oxidize to carboxylic acids using similar oxidizing agents. This reaction often referred to as the Cannizzaro reaction, where one molecule of the aldehyde reduced to an alcohol, while the other oxidized to a carboxylic acid.
c) HYDROLYSIS OF NITRILES:
Nitriles, which contain a cyano group (-CN), can hydrolyze to carboxylic acids under acidic or basic conditions. Acidic hydrolysis involves the addition of water and an acid catalyst, while basic hydrolysis utilizes a strong base such as sodium hydroxide (NaOH). The mechanism involves the formation of an imine intermediate, followed by hydrolysis to yield the carboxylic acid.
d) OXIDATION OF ALKENES OR ALKYNES:
Alkenes and alkynes can be oxidized by ozone (O3) followed by water (H2O) or mild oxidative conditions (such as potassium permanganate) to produce carboxylic acids.
2. REACTIONS OF CARBOXYLIC ACIDS:
Carboxylic acids can undergo esterification reactions, where they react with alcohols in the presence of an acid catalyst to form esters. This reaction is widely used in the synthesis of fragrances, flavors, and pharmaceuticals. The mechanism involves the formation of an intermediate acyl chloride, followed by nucleophilic attack by the alcohol to yield the ester.
Carboxylic acids can undergo decarboxylation reactions, where they lose a carbon dioxide molecule to form a substituted hydrocarbon. This reaction often catalyzed by heat or by the addition of a strong base. The mechanism involves the formation of a carboxylate anion, followed by the loss of carbon dioxide to yield the hydrocarbon.
c) REDUCTION OF CARBOXYLIC ACIDS:
Carboxylic acids can be reduced to primary alcohols using reducing agents such as lithium aluminum hydride (LiAlH4) or sodium borohydride (NaBH4). The mechanism involves the formation of an intermediate aldehyde, followed by further reduction to the alcohol.
Carboxylic acids are essential compounds in organic chemistry, with a wide range of preparations and reactions. Understanding the mechanisms behind these reactions allows chemists to design and synthesize complex molecules for various applications. This article has provided an overview of the preparations and reactions of carboxylic acids, along with references for further exploration. By delving deeper into this topic, researchers can uncover new applications and contribute to the advancement of organic chemistry.
March, J. (2007). Advanced Organic Chemistry: Reactions, Mechanisms, and Structure. Wiley-Interscience. https://rushim.ru/books/mechanizms/march6ed.pdf
Smith, M. B., & March, J. (2007). March’s Advanced Organic Chemistry: Reactions, Mechanisms, and Structure. Wiley. https://rushim.ru/books/mechanizms/march6ed.pdf
Clayden, J., Greeves, N., Warren, S., & Wothers, P. (2012). Organic Chemistry. Oxford University Press. https://global.oup.com/academic/product/organic-chemistry-9780199270293?cc=pk&lang=en&