Oxalyl Chloride

Definition

Oxalyl chloride is a highly reactive organic compound with the chemical formula (COCl)2. It is commonly used as a reagent in organic synthesis, particularly in the oxidation of alcohols to aldehydes or ketones.

5 Must Know Facts For Your Next Test

1. Oxalyl chloride is a colorless, pungent liquid that is highly reactive and must be handled with care.
2. It is commonly used in the oxidation of primary and secondary alcohols to aldehydes and ketones, respectively, in the presence of a base such as pyridine.
3. The reaction with oxalyl chloride generates an acyl chloride intermediate, which then reacts with the alcohol to form the desired carbonyl compound.
4. Oxalyl chloride is also used in the synthesis of various organic compounds, such as acid chlorides, esters, and amides.
5. Due to its high reactivity, oxalyl chloride must be stored and handled under anhydrous conditions to prevent hydrolysis and the formation of carbon dioxide and hydrochloric acid.

Review Questions

• Explain the role of oxalyl chloride in the oxidation of alcohols to aldehydes or ketones.
  • Oxalyl chloride is a useful reagent for the oxidation of alcohols to aldehydes or ketones. In this reaction, the oxalyl chloride first reacts with the alcohol to form an acyl chloride intermediate. The acyl chloride then undergoes a nucleophilic addition-elimination reaction with a base, such as pyridine, to generate the desired carbonyl compound (aldehyde or ketone). The chlorine atom from the acyl chloride is displaced, and the carbonyl carbon is left with an oxygen atom, forming the aldehyde or ketone product.
• Describe the reactivity and handling requirements of oxalyl chloride.
  • Oxalyl chloride is a highly reactive compound that must be handled with care. It is a colorless, pungent liquid that is prone to hydrolysis, forming carbon dioxide and hydrochloric acid. Due to its reactivity, oxalyl chloride must be stored and used under anhydrous conditions to prevent this unwanted side reaction. Additionally, the generation of HCl gas during the hydrolysis process makes it essential to perform reactions with oxalyl chloride in a well-ventilated area or under a fume hood. Proper personal protective equipment, such as gloves and goggles, should be used when working with this reagent to ensure safety.
• Analyze the versatility of oxalyl chloride in organic synthesis beyond its use in the oxidation of alcohols.
  • In addition to its use in the oxidation of alcohols, oxalyl chloride is a versatile reagent in organic synthesis. It can be employed in the preparation of various other organic compounds, such as acid chlorides, esters, and amides. The reactivity of the acyl chloride intermediate generated from oxalyl chloride allows for the introduction of new functional groups or the modification of existing ones. For example, the reaction of oxalyl chloride with a carboxylic acid can produce an acid chloride, which can then be further transformed into esters or amides through subsequent reactions. This versatility makes oxalyl chloride a valuable tool in the arsenal of organic chemists for the synthesis of complex organic molecules.

Related terms

Acyl Chloride:

A functional group containing a carbonyl carbon atom (C=O) bonded to a chlorine atom, commonly used as a reactive intermediate in organic reactions.

Oxidation:

A chemical reaction that involves the loss of electrons, resulting in an increase in the oxidation state of an element.

Aldehyde:

A class of organic compounds containing a carbonyl group (C=O) with a hydrogen atom attached to the carbon atom.