Question

The reagent that gives an acid chloride on treatement with a carboxylic acid is
$PC{l}_5,PC{l}_3,SOC{l}_2,RedP+C{l}_2$

• A. Only $PC{l}_5$
• B. Both $PC{l}_5$ and $PC{l}_3$
• C. Both $SOC{l}_2$ and $RedP+C{l}_2$
• D. $PC{l}_5,PC{l}_3,SOC{l}_2$

Answer 1

The correct option is D $PC{l}_5,PC{l}_3,SOC{l}_2$

Carboxylic acids react with phosphorous trichloride $\left(PC{l}_3\right)$, phosphorous pentachloride $\left(PC{l}_5\right)$, and thionyl chloride $\left(SOC{l}_2\right)$ to form acyl halides.
$RCOOH+PC{l}_5\to RCOCl+POC{l}_3+HCl$
$RCOOH+PC{l}_3\to RCOCl+H_{3}P{O}_3$
$RCOOH+SOC{l}_2\to RCOCl+S{O}_2+HCl$