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Reactions of Acyl Chlorides with Water

  • Page ID
    3794
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    This page gives you the facts and a simple, uncluttered mechanism for the nucleophilic addition / elimination reaction between acyl chlorides (acid chlorides) and water. Ethanoyl chloride is taken as a typical acyl chloride. Any other acyl chloride will behave in the same way. Simply replace the CH3 group in what follows by anything else you want.

    The facts

    Ethanoyl chloride reacts instantly with cold water. There is a very exothermic reaction in which a steamy acidic gas is given off (hydrogen chloride) and ethanoic acid is formed.

    OrganicCore_AcidHalides51.png

    The mechanism

    The first stage (the addition stage of the reaction) involves a nucleophilic attack on the fairly positive carbon atom by one of the lone pairs on the oxygen of a water molecule.

    OrganicCore_AcidHalides52.png

    The second stage (the elimination stage) happens in two steps. In the first, the carbon-oxygen double bond reforms and a chloride ion is pushed off.

    OrganicCore_AcidHalides53.png

    That is followed by removal of a hydrogen ion by the chloride ion to give ethanoic acid and hydrogen chloride.

    OrganicCore_AcidHalides54.png

    Contributors

    Jim Clark (Chemguide.co.uk)


    Reactions of Acyl Chlorides with Water is shared under a not declared license and was authored, remixed, and/or curated by Jim Clark.

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