Which reagent(s) can convert an Alcohol to a Haloalkane under reflux?

Master NCEA Level 3 Organic Chemistry Reaction Schemes. Prepare with multiple choice questions, complete with hints and detailed explanations. Ace your exam with our comprehensive tools!

Multiple Choice

Which reagent(s) can convert an Alcohol to a Haloalkane under reflux?

Transforming an alcohol into a haloalkane relies on turning the poor leaving group OH into something that can depart, then having chloride attack to form the C–Cl bond. Reagents that do this under reflux all do it by converting the hydroxyl into a better leaving group and delivering chloride. Thionyl chloride (SOCl2) does this in a single step: ROH plus SOCl2 gives RCl, with byproducts SO2 and HCl that escape as gases, which helps drive the reaction under heating. Phosphorus trichloride (PCl3) reacts with the alcohol to form a chlorinated product and phosphorous acid (H3PO3) as a byproduct, again replacing the OH with Cl. Phosphorus pentachloride (PCl5) acts similarly, producing RCl and phosphoric acid (H3PO4) as a byproduct. All three reagents are capable of converting alcohols to alkyl chlorides under reflux, so the best choice is that all of the above can perform the transformation.

Transforming an alcohol into a haloalkane relies on turning the poor leaving group OH into something that can depart, then having chloride attack to form the C–Cl bond. Reagents that do this under reflux all do it by converting the hydroxyl into a better leaving group and delivering chloride.

Thionyl chloride (SOCl2) does this in a single step: ROH plus SOCl2 gives RCl, with byproducts SO2 and HCl that escape as gases, which helps drive the reaction under heating. Phosphorus trichloride (PCl3) reacts with the alcohol to form a chlorinated product and phosphorous acid (H3PO3) as a byproduct, again replacing the OH with Cl. Phosphorus pentachloride (PCl5) acts similarly, producing RCl and phosphoric acid (H3PO4) as a byproduct. All three reagents are capable of converting alcohols to alkyl chlorides under reflux, so the best choice is that all of the above can perform the transformation.

More practice questions