Show how you would use an acid chloride as an intermediate to synthesize(a) N-phenylbenzamide $\left(\mathrm{PhCONHPh}\right)$from benzoic acid and aniline.(b) phenyl propionate$\left({\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{COOPh}\right)$ from propionic acid and phenol.

Acid chloride is activated form of carboxylic acid. In acid chloride, the carbonyl carbon is attached with oxygen and chlorine atom, which withdraws electron density from the carbon, making it strongly electrophilic.

Acid Chloride

The conversion of carboxylic acid to acid chloride occurs in the presence of thionyl chloride $\left({\mathrm{SOCl}}_2\right)$and oxalyl chloride $\left[\left({\mathrm{COCl}}_2\right)\right]$. The corresponding reaction is shown below.

conversion of carboxylic acid to Acid Chloride

From the above Figure, it is clear that there are two stereogenic centers of 10-camphorsulfonic and both stereogenic centers is R. Clopidogrel reacts with 10-camphorsulfonic acid to form diastereomers as shown below.

It is known that diastereomers are not superimposable or mirrored images of one another. Because diastereomers' physical and chemical properties differ from one another. They are easily distinguishable. As a result, the hydrolysis of both diastereomers yields clopidogrel enantiomers as shown below.