Question

the purification of the carboxylic acid derivative is facilitated by the differential solubilities of the starting material and product and the acidity of the carboxylic acid. in the purification, the reaction mixture is washed by 5 % naoh solution, which allows these species to be separated

Answer 1

Carboxylic acid derivatives are purified using methods that exploit their solubility and acidity differences, involving NaOH washes and column chromatography, aiding in the separation and characterization of the desired products.

Step-by-step explanation:

The purification of carboxylic acid derivatives is an important process in synthetic chemistry. By exploiting the differential solubility of starting materials and products, as well as the acidity of carboxylic acids, selective separation can be achieved. In a typical process, the carboxylic acid or its derivative is reacted with various reagents, such as EDC-HCl and HOBT, to form a coupled product with an amine.

The purification of the reaction mixture often involves washing with a 5% NaOH solution, which helps to separate the carboxylic acid or its derivatives, based on their solubility and reactivity differences.

Column chromatography is frequently used to obtain the purified product, especially after initial extraction and solvent removal steps. By using different solvent systems in the chromatography, such as EtOAc/petroleum ether or DCM/MeOH, a high degree of purity for the desired product can be achieved. This is crucial for obtaining reliable spectroscopic measurements, such as 1H-NMR and 13C NMR, which are used to characterize the final compound.